Bullet weight and Recoil [Archive] - Glock Talk

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vefrancis
02-03-2012, 15:04
With factory ammo does the bullet weight have any correlation with the amount of recoil? Example: Does a 155 grain winchester ranger have less recoil than a 180gr winchester ranger?

JBP55
02-03-2012, 15:16
Just the opposite. In the same type ammunition the heavier round is slightly softer shooting and will impact slightly higher on target compared to the lighter round.

DannyR
02-03-2012, 15:26
The two variables are bullet weight and muzzle velocity.

3/4Flap
02-03-2012, 15:40
Uh...

Normally the heavier bullet generates heavier recoil. This is of course not always true as what DannyR said is also true.

In other words, it is possible that either BULLET weight may generate heavier or lighter recoil, based on the velocity of the bullet.

Basically, with two cartridges generating similar pressures, the heavier bullet load will kick more.

And...

Powder weight also contributes to recoil. This is more noticeable in heavy kicking rifles due to the quantity used {may not even be noticed in pistols}. Powder forms part of the projectile mass of the load until it is burned.

frontier2011
02-03-2012, 15:45
Just the opposite. In the same type ammunition the heavier round is slightly softer shooting and will impact slightly higher on target compared to the lighter round.

Thats weird. The 180gr 'kick' a lot more than a 165 gr in my glock.

Does the 180 gr and the 165 gr have the same amount of gun powder?

NucPhysics
02-03-2012, 15:57
DannyR is correct, it is both mass of bullet (m) and muzzle velocity (v),

The law is called the conservation of momentum:

m x v = m x v

The momentum in one direction is equal and opposite to the momentum in the opposite direction.

Thus, the heavier/faster the bullet, the more the recoil.

I am a Physicist and I approve of this equation. http://www.glocktalk.com/forums/images/smilies/wavey%5B1%5D.gif

3/4Flap
02-03-2012, 16:10
Thats weird. The 180gr 'kick' a lot more than a 165 gr in my glock.



In general, your experience is correct.

3/4Flap
02-03-2012, 16:13
DannyR is correct, it is both mass of bullet (m) and muzzle velocity (v),

The law is called the conservation of momentum:

m x v = m x v

The momentum in one direction is equal and opposite to the momentum in the opposite direction.

Thus, the heavier/faster the bullet, the more the recoil.

I am a Physicist and I approve of this equation. http://www.glocktalk.com/forums/images/smilies/wavey%5B1%5D.gif

Don't forget priming compound, powder and mass of the gun itself that absorbs some of the energy causing differences in felt recoil.

i.e. a G29 kicks more with the same loads as does a G20.

I know...gun for gun. ;)

Just flipping you you-know-what. ;)

NucPhysics
02-03-2012, 16:33
3/4Flap,

You are exactly correct, it depends on the gun as the gun needs to be the same. A heavier gun has more inertia (resistance to move) and thus would dampen the felt recoil.

As far as powder charge, primer, crimp, bullet setback, and whatnot, they are irrelavant as the resultant muzzle velocity has already incorporated that into the mechanics.

One thing that isn't accounted for in "felt recoil" is the height of the barrel. Even though the recoil is the same with a higher barrel axis, bore axis, the more torque may make it feel as though there is more recoil even though there isn't. It's merely perception thing.

3/4Flap
02-03-2012, 17:01
3/4Flap,


As far as powder charge, primer, crimp, bullet setback, and whatnot, they are irrelavant as the resultant muzzle velocity has already incorporated that into the mechanics.


Wait...

Take a .45-70 rifle shooting a 500 grain bullet at 1150 fps using two loads.

One uses 70 grains of Black Powder to accomplish this.

The other uses 22 grains of smokeless.

Recoil energy is greater with the black powder by any measurement, so what is the cause?

Pierre!
02-03-2012, 17:26
Then there is the slide speed...

This seems to affect the transfer of recoil feeling, as well as changing the timing of the event.

My personal experience is:
220gr or 200gr bullets shoot *softer* but also have a slow slide speed - more of a push feeling
180gr seem to be a nice blend of slide speed and manageable recoil
165gr have a *snap* to the recoil, but you are back on target quickly!

When it doubt, try it out... Not easy to find 220gr loads for .40, but you should be able to find 200gr and 180gr pretty easily.

Let us know what you find out!

Patrick

JBP55
02-03-2012, 17:55
DannyR is correct, it is both mass of bullet (m) and muzzle velocity (v),

The law is called the conservation of momentum:

m x v = m x v

The momentum in one direction is equal and opposite to the momentum in the opposite direction.

Thus, the heavier/faster the bullet, the more the recoil.

I am a Physicist and I approve of this equation. http://www.glocktalk.com/forums/images/smilies/wavey%5B1%5D.gif


HST 180gr. 1010 FPS 408 energy. 180X1010=181,800
HST 165gr. 1130 FPS 468 energy. 165X1130=186,450
Do the math and get back with us.

barth
02-03-2012, 18:00
It's a combination of weight and velocity.
40 doesn't have +P or +P+ ratings.
But ammo is loaded a little differently depending on the manufacturer.
Most 180s are sub sonic and relativity soft shooting.
The 135/155s are usually loaded hot.
165 can be hot or cold - it depends...

Example:
Federal Hydra-Shok 165
980 fps 352 E

Speer GDHP 165
1150 fps 484 E

Guess which one kicks harder - LOL!

ron59
02-03-2012, 18:38
I'm not buying any of this.

I'm a competition shooter and reloader. USPSA 'B' shooter and missed Expert in IDPA by less than a half-second last year, I expect to easily make it this year.

In "the games" (IDPA/USPSA), they compare bullet weights by using a computation called Power Factor. That is bullet weight times velocity.

They will usually then declare a minimum Power Factor that can be made, such as 125,000 (often called 125PF). For example, a 115gr 9mm bullet traveling 1150fps has a power factor of 132,250 (or abbreviated 132PF). That's pretty close to WWB 115gr 9mm FMJ bullet.

I shoot 147gr bullets, loaded to a similar PF. I load them to achieve velocity of around 915fps for a PF of 134PF.

The result? The 147gr round has a MUCH softer recoil than the 115gr bullet.

I have done this "test" with multiple friends, all who have done it have agreed with me. Take a magazine and load it with 10 rounds, 5 of 115gr WWB and 5 of my 147gr reload. Alternate them so you'll fire one first, then the other. The "softness" of the 147gr will put a smile on your face.

Some people's reaction is "you're comparing a HOT 115gr to a SOFT 147gr round". And I would disagree with that. The 115gr WWB round is by no means hot. And there is no way a 147grainer at 915fps could be considered soft. I think Speer Gold Dot 147grain bullets only reach 950fps or so out of a G17 sized gun (the size these comparisons and measurements were made through). 915fps is not *that* far off of 915fps.... not considering when I COULD load it way down to 850fps and still (almost) make minimum power factor.

I would suspect that these same results would be seen for any round, whether it is .40 or .45ACP.

I have converted several of my gaming reloading friends to shooting 147gr bullets just because of this. It is not hearsay, it is not myth, but fact. I have a chrono and chrono all my loads, as well as some factory loads for comparison sake.

Talk about pressures, talk about barrels, etc has no bearing. As long as your pressures are safe and you use the same barrel to compare, those points are moot. So are pretty much any other piece of "evidence" listed above.

Use ONE gun (the same gun). Take a lighter round and a heavier round of the same PF and shoot them through it, alternating as I described above. Money says the heavier round will feel softer.

JBP55
02-03-2012, 18:45
My three posts are in agreement with ron59 and if you shoot the different weight rounds you will understand.

ron59
02-03-2012, 19:15
My three posts are in agreement with ron59 and if you shoot the different weight rounds you will understand.

This is key. Not talking about pressure, or anything else. But true objective research.

1) It is important that the two rounds have fairly close Power Factor. That is the only method I've ever seen to try and compare the "power" of two different rounds. There's a reason why the gaming organizations use that computation, it works.

2) It is possible to bias the results by not following #1. I made the assumption that most typical factory 115gr ammo was loaded similarly. It is not. When I did my test using my ammo vs some Federal Champion my one shooting buddy had, I was surprised to see that I could not tell ANY difference between the two loads. I literally could not tell the difference between his 115gr load and my 147gr load.

I then chronographed the Fed Champion ammo. VERY WEAK AMMO. It barely was getting 125PF, quite a difference from the 132-133PF from the WWB. And thus the difference. I never did any accuracy tests with that ammo, but I know if you try and slow down a 147gr bullet too much (trying to achieve maximum softness), it *will* affect bullet accuracy. Which is why I run mine at 915-920fps. I suspect those Fed Champions *might* not be as accurate as the WWB.

frontier2011
02-03-2012, 19:23
thats weird. The 180gr 'kick' a lot more than a 165 gr in my glock.

Does the 180 gr and the 165 gr have the same amount of gun powder?

ne1??

3/4Flap
02-03-2012, 19:57
Look, what you guys are describing is as I said; velocity is a factor as well as bullet weight.

If you are shooting low velocity rounds like common service pistol rounds, the recoil is so similar between different loads it is relatively "the same", with different shooters often judging different rounds opposite as per felt recoil.

In rifles where the recoil is better "felt", heavier bullets in loads generating similar breech pressures generally generate heavier recoil.

felt recoil is an interesting phenomenon. I always felt my .357 SIG 226 kicked less than my 9x19. One pistol had the solid slide, the other the folded slide, but still...

Step up to the .44 Mag and you see in handguns the GENERAL rule-of-thumb applying.

Also, NucPhysics, my question was at face value.

abq87120
02-03-2012, 19:59
My G23 shoots 180g imperceptably softer than the 165g.

NucPhysics
02-03-2012, 20:04
We're starting to talk two different concepts: actual recoil and perceived recoil.

Actual recoil is what many here have already said is based on muzzle velocity and bullet weight which is what I thought the original question was asking. It's a straight forward physics concept - however, as long as everything else is all equal.

Perceived recoil is something many others here are bringing up and with many good points as well. The actuation of the slide, the slide slamming back on the RSA, the speed of the reaction, etc, etc. All good points. All effect the perception of recoil and how we will all perceive it differently.

An analogy of actual/perception is lifting a 200 lb weight over your head vs. a 20 lb weight 10 times. One is definitely easier but the ultimate work is the same (Work = force x distance). The first feels like more work, as it does to me, but the work is technically the same when calculated. Also, Temperatures can feel differently based on humidity or wind but actual temperature is still the same regardless of how of we perceive it.

Sorry I oversimplified earlier to actual recoil, but many of you have had good points on how and under different conditions recoil can be perceived differently, and there is no legitimate argument against different perceptions.

NucPhysics
02-03-2012, 20:20
3/4Flap, Thank you for bringing up some very good examples. I can't feel any difference between my G22 and my G19 even though everyone else tells me they feel completely differently to them. Just because we can calculate something based on the rules of physics doesn't mean that's how we will feel it. I know I am a bad example. http://www.glocktalk.com/forums/images/smilies/wavey%5B1%5D.gif

frontier2011
02-03-2012, 20:29
F =ma

barth
02-03-2012, 20:32
Velocity and Weight of the bullet together affect recoil.

In terms of felt recoil; the weight of the gun, length of the barrel and grips play a part as well.

Finally, in comparison of revolvers vs auto-loaders,
the act of driving the slide absorbs a good deal of the felt recoil.

And then there's compensators, ports, muzzle brakes... LOL

3/4Flap
02-03-2012, 20:52
Velocity and Weight of the bullet together affect recoil.



Nope.

Weight of the projectile mass; might be bullet & UNburnt powder, or bullet and wads & UNburnt powder, or bullet and UNburnt powder. It is NOT just the bullet that effect recoil, it is the projectile mass. {and velocitiy of it}

Nuc still needs to address how the black powder/smokeless load example I quoted works.

The BP recoil is not just "perceptibly" heavier in recoil it IS heavier in recoil.

Powder mass effects recoil. It must be factored into the equation, tho don't ask me for the formula. That's above my pay grade...

1canvas
02-03-2012, 21:11
for my hunting revolvers heavier bullets at max always recoiled more than lighter bullets at max, although the lighter bullets blow a lot more blast. i always thought the recoil thing in .40 auto pistols was a case capacity issue, the longer bullet limmiting case capacity.

barth
02-03-2012, 21:15
Nope.

Weight of the projectile mass; might be bullet & UNburnt powder, or bullet and wads & UNburnt powder, or bullet and UNburnt powder. It is NOT just the bullet that effect recoil, it is the projectile mass. {and velocitiy of it}

Nuc still needs to address how the black powder/smokeless load example I quoted works.

The BP recoil is not just "perceptibly" heavier in recoil it IS heavier in recoil.

Powder mass effects recoil. It must be factored into the equation, tho don't ask me for the formula. That's above my pay grade...

The bullet is the projectile.
But you are very funny...

3/4Flap
02-03-2012, 21:15
for my hunting revolvers heavier bullets at max always recoiled more than lighter bullets at max, although the lighter bullets blow a lot more blast. i always thought the recoil thing in .40 auto pistols was a case capacity issue, the longer bullet limmiting case capacity.

Yup.

Thanks for posting.

You make a good point in that the .40 is a very small case for its caliber; powder capacity is very limited. I don't doubt for a moment that some .40 loads with heavy bullets recoil less or similarly to lighter bullets.

M.O.A.
02-03-2012, 21:17
It also seems that crimp would come into play as well. The more crimp a bullet has the longer it stays in the case after ignition which causes pressures to rise dramatically. C.O.L. would also come into play.

barth
02-03-2012, 21:19
9x19 Win Ranger +P+ |115@1320, 21.7 mv, 444 E|BR 9.6", 0.53", 2.11cu|CL 10.2", 0.65", 3.37cu|avg 2.74, 3.89 re, 0.70
9x19 - caliber
Win Ranger +P+ - the name of the load
115@1320 - bullet mass in grains @ muzzle velocity
21.7 mv - bullet momentum in lb*fps
444 E - muzzle energy in ftlbs
BR - what follows is the data for bare gelatin
9.6" inches of penetration
0.53", final expanded diameter of bullet
2.11 cu, approximation of wound volume. (this does not take into account the expansion profile as a function of depth, but it should be roughly proportionate to actual wound volume)
CL - what follows is the data for clothed gelatin
same fields as the bare gelatin, as defined above
avg 2.74 - Average wound volume, clothed and bare gelatin
3.89 re - Free Recoil Energy, assuming a 1.88 lb pistol
0.70 - Average would volume per unit Free Recoil Energy.
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
9x19 Win Ranger Talon|147@ 864, 18.1 mv, 243 E|BR 13.8", 0.61", 4.03cu|CL 15.2", 0.59", 4.17cu|avg 4.10, 2.72 re, 1.51
9x19 Win Ranger Talon|147@1017, 21.4 mv, 337 E|BR 13.8", 0.66", 4.70cu|CL 15.5", 0.65", 5.14cu|avg 4.92, 3.77 re, 1.31
9x19 Win Ranger +P+ |115@1320, 21.7 mv, 444 E|BR 9.6", 0.53", 2.11cu|CL 10.2", 0.65", 3.37cu|avg 2.74, 3.89 re, 0.70
9x19 3-D |115@1178, 19.4 mv, 354 E|BR 11.6", 0.54", 2.66cu|CL 13.9", 0.48", 2.52cu|avg 2.59, 3.10 re, 0.84
9x19 Rem +P+ |115@1221, 20.1 mv, 380 E|BR 10.8", 0.63", 3.37cu|CL 10.9", 0.62", 3.29cu|avg 3.33, 3.33 re, 1.00
9x19 CCI/Speer GD |115@1259, 20.7 mv, 404 E|BR 12.3", 0.67", 4.35cu|CL 22.1", 0.40", 2.78cu|avg 3.43, 3.54 re, 0.97
9x19 CCI/Speer GD |115@1197, 19.7 mv, 365 E|BR 12.8", 0.67", 4.51cu|CL 22.6", 0.44", 3.44cu|avg 3.78, 3.20 re, 1.18
9x19 CorBon +P |115@1317, 21.6 mv, 442 E|BR 8.9", 0.52", 1.90cu|CL 10.2", 0.61", 2.98cu|avg 2.44, 3.87 re, 0.63
9x19 Fed +P |115@1237, 20.3 mv, 390 E|BR 11.2", 0.53", 2.48cu|CL 10.6", 0.62", 3.20cu|avg 2.84, 3.41 re, 0.83
9x19 Fed Silvertip |115@1091, 17.9 mv, 304 E|BR 10.1", 0.63", 3.13cu|CL 11.8", 0.58", 3.12cu|avg 3.13, 2.66 re, 1.18
9x19 CCI/Speer GD +P |124@1223, 21.7 mv, 411 E|BR 13.4", 0.68", 4.87cu|CL 20.2", 0.53", 4.47cu|avg 4.64, 3.88 re, 1.20
9x19 CCI/Speer GD |124@1116, 19.8 mv, 342 E|BR 11.8", 0.69", 4.41cu|CL 22.0", 0.36", 2.24cu|avg 3.22, 3.23 re, 1.00
9x19 Rem |124@1109, 19.6 mv, 338 E|BR 12.4", 0.60", 3.52cu|CL 13.7", 0.57", 3.50cu|avg 3.51, 3.19 re, 1.10
9x19 PMC/Eldorado SF |124@1118, 19.8 mv, 344 E|BR 10.7", 0.63", 3.32cu|CL 20.1", 0.41", 2.65cu|avg 2.98, 3.24 re, 0.92
9x19 CorBon XTP |124@1123, 19.9 mv, 347 E|BR 13.9", 0.56", 3.44cu|CL 18.3", 0.46", 3.04cu|avg 3.24, 3.27 re, 0.99
9x19 Fed HydraShok |147@ 935, 19.6 mv, 285 E|BR 13.6", 0.60", 3.85cu|CL 16.1", 0.52", 3.41cu|avg 3.63, 3.19 re, 1.14
9x19 Win Black Talon |147@ 946, 19.9 mv, 292 E|BR 14.8", 0.60", 4.20cu|CL 16.4", 0.61", 4.78cu|avg 4.49, 3.26 re, 1.38
9x19 Rem |147@ 987, 20.7 mv, 318 E|BR 18.1", 0.51", 3.71cu|CL 15.9", 0.59", 4.36cu|avg 4.03, 3.55 re, 1.14
9x19 Hornady XTP |147@ 918, 19.3 mv, 275 E|BR 22.1", 0.44", 3.36cu|CL 20.5", 0.46", 3.41cu|avg 3.18, 3.07 re, 1.04
9x19 Fed HydraShok |147@ 995, 20.9 mv, 323 E|BR 21.4", 0.37", 2.30cu|CL 15.6", 0.60", 4.41cu|avg 3.28, 3.61 re, 0.91
9x19 Win Silvertip |147@ 902, 18.9 mv, 265 E|BR 14.6", 0.53", 3.22cu|CL 18.1", 0.47", 3.14cu|avg 3.18, 2.97 re, 1.07
9x19 CCI/Speer GD+P |124@1155, 20.5 mv, 367 E|BR 13.2", 0.62", 3.99cu|CL 16.1", 0.53", 3.55cu|avg 3.77, 3.46 re, 1.09
9x19 CCI/Speer GD |124@1068, 18.9 mv, 314 E|BR 12.6", 0.59", 3.44cu|CL 17.5", 0.51", 3.57cu|avg 3.51, 2.96 re, 1.19
9x19 CCI/Speer GD |147@ 924, 19.4 mv, 278 E|BR 14.8", 0.57", 3.78cu|CL 14.7", 0.55", 3.49cu|avg 3.63, 3.11 re, 1.17
9x19 Win Ranger PG |124@1015, 18.0 mv, 283 E|BR 12.5", 0.65", 4.15cu|CL 14.0", 0.61", 4.09cu|avg 4.12, 2.67 re, 1.54
9x19 Win Ranger T |147@1016, 21.3 mv, 337 E|BR 13.8", 0.66", 4.72cu|CL 15.7", 0.00", 0.00cu|avg 2.36, 3.76 re, 0.63
357SIG CCI/Speer GD |125@1372, 24.5 mv, 522 E|BR 16.1", 0.60", 4.54cu|CL 19.1", 0.54", 4.36cu|avg 4.45, 4.96 re, 0.90
40SW Win Ranger Talon|180@1000, 25.7 mv, 399 E|BR 13.6", 0.68", 4.92cu|CL 13.5", 0.68", 4.90cu|avg 4.91, 5.47 re, 0.90
40SW CCI/Speer GD |155@1176, 26.0 mv, 475 E|BR 10.7", 0.84", 5.93cu|CL 18.1", 0.57", 4.62cu|avg 5.27, 5.61 re, 0.94
40SW CCI/Speer GD |155@1186, 26.3 mv, 483 E|BR 10.7", 0.84", 5.93cu|CL 17.7", 0.58", 4.68cu|avg 5.30, 5.70 re, 0.93
40SW Hornady XTP |155@1194, 26.4 mv, 490 E|BR 14.5", 0.65", 4.81cu|CL 18.1", 0.55", 4.30cu|avg 4.56, 5.78 re, 0.79
40SW Win Silvertip |155@1199, 26.5 mv, 494 E|BR 12.2", 0.69", 4.54cu|CL 13.2", 0.71", 5.21cu|avg 4.87, 5.83 re, 0.84
40SW Fed Hi-Shok |155@1167, 25.8 mv, 468 E|BR 13.8", 0.61", 4.02cu|CL 19.5", 0.51", 3.98cu|avg 4.00, 5.52 re, 0.72
40SW CCI/Speer GD |165@1076, 25.4 mv, 424 E|BR 13.1", 0.65", 4.33cu|CL 15.8", 0.60", 4.47cu|avg 4.40, 5.32 re, 0.83
40SW Fed HydraShok |165@1007, 23.7 mv, 371 E|BR 13.8", 0.62", 4.18cu|CL 15.2", 0.64", 4.87cu|avg 4.53, 4.66 re, 0.97
40SW Rem |165@1031, 24.3 mv, 389 E|BR 12.5", 0.67", 4.41cu|CL 16.3", 0.61", 4.76cu|avg 4.59, 4.88 re, 0.94
40SW Fed HydeaShok |165@ 931, 21.9 mv, 317 E|BR 15.8", 0.58", 4.19cu|CL 21.1", 0.43", 3.06cu|avg 3.55, 3.98 re, 0.89
40SW Rem G.S. |165@ 952, 22.4 mv, 332 E|BR 13.1", 0.64", 4.21cu|CL 20.0", 0.53", 4.41cu|avg 4.31, 4.16 re, 1.04
40SW Rem G.S. |165@1022, 24.1 mv, 382 E|BR 14.8", 0.65", 4.89cu|CL 14.3", 0.66", 4.91cu|avg 4.90, 4.80 re, 1.02
40SW Fed HydraShok |165@ 943, 22.2 mv, 325 E|BR 18.2", 0.63", 5.69cu|CL 19.4", 0.56", 4.77cu|avg 5.23, 4.08 re, 1.28
40SW Win Ranger T. |180@ 947, 24.4 mv, 358 E|BR 13.8", 0.69", 5.14cu|CL 13.7", 0.70", 5.25cu|avg 5.20, 4.90 re, 1.06
40SW CCI/Speer GD |180@ 982, 25.3 mv, 385 E|BR 14.5", 0.59", 3.96cu|CL 17.6", 0.60", 4.96cu|avg 4.46, 5.27 re, 0.85
40SW Rem G.S. |180@ 931, 23.9 mv, 346 E|BR 16.8", 0.69", 6.28cu|CL 16.9", 0.63", 5.28cu|avg 5.78, 4.74 re, 1.22
40SW Rem G.S. |180@ 945, 24.3 mv, 356 E|BR 16.9", 0.64", 5.44cu|CL 21.0", 0.43", 3.05cu|avg 4.17, 4.88 re, 0.85
40SW Rem G.S. |180@ 893, 23.0 mv, 318 E|BR 15.7", 0.65", 5.19cu|CL 21.1", 0.51", 4.32cu|avg 4.64, 4.36 re, 1.06
40SW CCI/Speer GD |180@ 958, 24.6 mv, 366 E|BR 14.6", 0.60", 4.13cu|CL 17.1", 0.62", 5.16cu|avg 4.65, 5.02 re, 0.93
40SW Rem G.S. |180@ 954, 24.5 mv, 363 E|BR 14.8", 0.66", 5.06cu|CL 14.8", 0.67", 5.20cu|avg 5.13, 4.98 re, 1.03
40SW Win B.T. |180@ 917, 23.6 mv, 336 E|BR 13.5", 0.69", 5.05cu|CL 14.4", 0.70", 5.54cu|avg 5.29, 4.60 re, 1.15
40SW Hornady XTP |180@ 929, 23.9 mv, 345 E|BR 13.9", 0.64", 4.49cu|CL 18.4", 0.55", 4.38cu|avg 4.44, 4.72 re, 0.94
40SW Fed HydraShok |180@ 969, 24.9 mv, 375 E|BR 14.2", 0.69", 5.29cu|CL 19.8", 0.59", 5.41cu|avg 5.35, 5.13 re, 1.04
40SW Fed Hi-Shok |180@ 960, 24.7 mv, 368 E|BR 14.8", 0.66", 5.05cu|CL 24.0", 0.47", 4.16cu|avg 4.26, 5.04 re, 0.85
40SW Win Ranger SXT |180@ 905, 23.3 mv, 327 E|BR 11.2", 0.70", 4.31cu|CL 13.0", 0.64", 4.18cu|avg 4.25, 4.48 re, 0.95
40SW Win Ranger PG |165@1109, 26.1 mv, 450 E|BR 13.1", 0.73", 5.48cu|CL 14.5", 0.72", 5.90cu|avg 5.69, 5.65 re, 1.01
40SW Win Ranger T |180@ 943, 24.2 mv, 355 E|BR 13.6", 0.68", 4.94cu|CL 14.6", 0.70", 5.62cu|avg 5.28, 4.86 re, 1.09
45ACP CCI/Speer GD |185@1041, 27.5 mv, 445 E|BR 11.9", 0.68", 4.34cu|CL 14.8", 0.68", 5.36cu|avg 4.85, 6.26 re, 0.77
45ACP Rem G.S. |185@1037, 27.4 mv, 441 E|BR 14.4", 0.72", 5.86cu|CL 15.9", 0.68", 5.79cu|avg 5.83, 6.21 re, 0.94
45ACP Rem G.S. +P |185@1046, 27.6 mv, 449 E|BR 10.1", 0.87", 6.00cu|CL 9.5", 0.81", 4.90cu|avg 5.45, 6.32 re, 0.86
45ACP Fed Hi-Shok |185@ 874, 23.1 mv, 313 E|BR 11.7", 0.74", 5.03cu|CL 19.8", 0.61", 5.79cu|avg 5.41, 4.41 re, 1.23
45ACP Win Silvertip |185@ 951, 25.1 mv, 371 E|BR 10.7", 0.78", 5.11cu|CL 10.9", 0.73", 4.56cu|avg 4.84, 5.22 re, 0.93
45ACP Fed Hi-Shok |185@ 953, 25.2 mv, 373 E|BR 13.3", 0.63", 4.15cu|CL 12.4", 0.74", 5.33cu|avg 4.74, 5.24 re, 0.90
45ACP Rem |185@ 903, 23.9 mv, 335 E|BR 16.2", 0.70", 6.23cu|CL 24.6", 0.55", 5.83cu|avg 5.49, 4.71 re, 1.17
45ACP CCI/Speer GD +P |200@1062, 30.3 mv, 500 E|BR 11.7", 0.75", 5.17cu|CL 18.8", 0.55", 4.47cu|avg 4.82, 7.61 re, 0.63
45ACP Fed HydraShok |230@ 956, 31.4 mv, 466 E|BR 13.8", 0.72", 5.64cu|CL 13.6", 0.74", 5.83cu|avg 5.73, 8.16 re, 0.70
45ACP Fed HydraShok |230@ 878, 28.8 mv, 393 E|BR 16.6", 0.66", 5.66cu|CL 20.2", 0.55", 4.80cu|avg 5.21, 6.88 re, 0.76
45ACP Fed HydraShok |230@ 858, 28.2 mv, 375 E|BR 13.7", 0.71", 5.42cu|CL 16.4", 0.66", 5.59cu|avg 5.51, 6.57 re, 0.84
45ACP Win |230@ 802, 26.4 mv, 328 E|BR 17.9", 0.60", 5.06cu|CL 24.0", 0.51", 4.90cu|avg 4.57, 5.74 re, 0.80
45ACP Fed HydraShok |230@ 854, 28.1 mv, 372 E|BR 14.9", 0.71", 5.90cu|CL 15.4", 0.64", 4.97cu|avg 5.43, 6.51 re, 0.83
45ACP Rem G.S. |230@ 885, 29.1 mv, 399 E|BR 14.1", 0.76", 6.37cu|CL 16.6", 0.69", 6.19cu|avg 6.28, 6.99 re, 0.90
45ACP Win Ranger SXT |230@ 819, 26.9 mv, 342 E|BR 13.2", 0.73", 5.55cu|CL 17.9", 0.63", 5.56cu|avg 5.55, 5.99 re, 0.93
45ACP CCI/Speer GD |230@ 896, 29.4 mv, 409 E|BR 16.0", 0.69", 5.98cu|CL 18.9", 0.59", 5.17cu|avg 5.58, 7.17 re, 0.78
45ACP PMC/Eldorado SF |230@ 853, 28.0 mv, 371 E|BR 13.9", 0.67", 4.90cu|CL 22.6", 0.45", 3.59cu|avg 4.04, 6.49 re, 0.62
45ACP Rem G.S. |230@ 871, 28.6 mv, 387 E|BR 15.0", 0.71", 5.94cu|CL 18.9", 0.73", 7.89cu|avg 6.91, 6.77 re, 1.02
45ACP CCI/Speer GD |230@ 847, 27.8 mv, 366 E|BR 13.2", 0.74", 5.66cu|CL 14.3", 0.70", 5.50cu|avg 5.58, 6.40 re, 0.87
45ACP Fed Hi-Shok |230@ 860, 28.3 mv, 377 E|BR 13.8", 0.80", 6.96cu|CL 17.4", 0.67", 6.13cu|avg 6.55, 6.60 re, 0.99
45ACP Win. B.T. |230@ 886, 29.1 mv, 400 E|BR 11.9", 0.77", 5.56cu|CL 13.9", 0.74", 6.00cu|avg 5.78, 7.01 re, 0.83
10mm Norma |170@1358, 33.0 mv, 695 E|BR 16.6", 0.59", 4.52cu|CL 17.0", 0.63", 5.30cu|avg 4.91, 8.99 re, 0.55
10mm CCI/Speer PHP |180@ 992, 25.5 mv, 393 E|BR 15.8", 0.72", 6.44cu|CL 17.5", 0.61", 5.11cu|avg 5.78, 5.38 re, 1.07
10mm Win Black Talon |200@ 901, 25.7 mv, 360 E|BR 13.9", 0.67", 4.90cu|CL 15.6", 0.67", 5.50cu|avg 5.20, 5.48 re, 0.95
10mm Hornady XTP |200@1056, 30.2 mv, 495 E|BR 21.4", 0.58", 5.65cu|CL 24.1", 0.52", 5.13cu|avg 4.77, 7.53 re, 0.63
357MAG Rem G.S. |125@1220, 21.8 mv, 413 E|BR 14.4", 0.56", 3.55cu|CL 20.6", 0.48", 3.72cu|avg 3.58, 3.92 re, 0.91
357MAG Fed JHP |125@1265, 22.6 mv, 444 E|BR 10.7", 0.49", 2.01cu|CL 11.8", 0.51", 2.40cu|avg 2.20, 4.22 re, 0.52
357MAG Win Silvertip |145@1166, 24.2 mv, 437 E|BR 15.8", 0.58", 4.17cu|CL 12.9", 0.64", 4.15cu|avg 4.16, 4.82 re, 0.86
357MAG Fed JHP |158@1200, 27.1 mv, 505 E|BR 16.5", 0.50", 3.24cu|CL 15.9", 0.64", 5.12cu|avg 4.18, 6.07 re, 0.69
.380 Win Silvertip | 85@ 954, 11.6 mv, 172 E|BR 7.9", 0.58", 2.09cu|CL 9.1", 0.47", 1.58cu|avg 1.83, 1.11 re, 1.65
.380 CCI/Speer GD | 88@ 914, 11.5 mv, 163 E|BR 11.6", 0.46", 1.92cu|CL 17.2", 0.35", 1.66cu|avg 1.79, 1.09 re, 1.64
.380 CCI/Speer GD | 90@ 934, 12.0 mv, 174 E|BR 9.3", 0.59", 2.54cu|CL 11.3", 0.49", 2.14cu|avg 2.34, 1.19 re, 1.96
.380 Fed HydraShok | 90@ 971, 12.5 mv, 188 E|BR 6.7", 0.66", 2.29cu|CL 12.0", 0.49", 2.26cu|avg 2.28, 1.29 re, 1.77

M.O.A.
02-03-2012, 21:20
My eyes are crossed now.

3/4Flap
02-03-2012, 21:26
The bullet is the projectile.
But you are very funny...

And you are wrong.

The projectile is that which is expelled up the bore and out. That includes bullet AND powder mass as it burns.

Seriously, you guys need to take some time and study some basic internal ballistics.

By the way, your list of loads demonstrates the point. In low powder capacity caes, the recoil of light and heavy bullets is similar. As powder capacity increases with its concurrent ability to increase velocity of heavier bullets, the disparity is made more apparent.

ron59
02-03-2012, 21:30
I don't carry about numbers, other than insuring I'm comparing apples-to-apples (similar Power Factor, as I described earlier).

And I don't care about "actual" recoil (not even sure what that means or how to determine it). I'm talking about taking those rounds and shooting them and seeing how it FEELS.

I don't like calling it "perceived" recoil either, because when you start talking perceptions, what I perceive might be different from what you perceive. However... in the case I described earlier? I find it hard to believe that someone would say that they perceived the 115gr load to be softer.

If everyone agrees on something, it goes from "perception" to fact.

Dang. I'm getting too deep even for myself. That last sentence doesn't sound right to me, but I can't think of a better way to say it.

sandpiper
02-03-2012, 21:30
DannyR is correct, it is both mass of bullet (m) and muzzle velocity (v),

The law is called the conservation of momentum:

m x v = m x v

The momentum in one direction is equal and opposite to the momentum in the opposite direction.

Thus, the heavier/faster the bullet, the more the recoil.

I am a Physicist and I approve of this equation. http://www.glocktalk.com/forums/images/smilies/wavey%5B1%5D.gif

I love Glocktalk

NucPhysics
02-03-2012, 21:35
Nope.

Weight of the projectile mass; might be bullet & UNburnt powder, or bullet and wads & UNburnt powder, or bullet and UNburnt powder. It is NOT just the bullet that effect recoil, it is the projectile mass. {and velocitiy of it}

Nuc still needs to address how the black powder/smokeless load example I quoted works.

The BP recoil is not just "perceptibly" heavier in recoil it IS heavier in recoil.

Powder mass effects recoil. It must be factored into the equation, tho don't ask me for the formula. That's above my pay grade...

BTW, You did better clarify the mass (m) as being the entire projectile - unburnt powder, the wad if present, and anything else ejected forward.

As for the BP example you stated above, I am not positive but I could make a reasonable guess that it could relate to the propellant (BP) still burning and forcing the gun back with added force even though the bullet has exited the barrel, thus the extra kick that you and everyone feels. (Please note this is my best guess based on limited knowledge of BP guns). Whatever the case, all momentum forward still must equal momentum backward.

NucPhysics
02-03-2012, 21:44
It also seems that crimp would come into play as well. The more crimp a bullet has the longer it stays in the case after ignition which causes pressures to rise dramatically. C.O.L. would also come into play.

I agree with this. The higher the pressure develops though, the faster the bullet, meaning more recoil.

All other things equal, anything that translates to a faster bullet (or projectile) would mean more recoil.

davsco
02-03-2012, 22:00
if i remember correctly from way back when i took a couple of physics courses, energy = 1/2 mass x velocity squared, not just mass times velocity.

mass x velocity is a formula used in idpa and uspsa to determine what they call power factor.

so looking at federal's website for their .40 S&W, American Eagle ammo, the 155 grain at 1160fps gives 463 ft-lbs of energy, while their heavier 180grain at 1000fps gives 400 ft-lbs of energy. so energy drops almost 16%, with velocity dropping just 14% but bullet weight increasing 16%.

i agree that trying to compare, for example, a 9mm vs a .45 isn't as simple as the math above due to differences in guns, weight and balance, etc.

NucPhysics
02-03-2012, 22:07
if i remember correctly from way back when i took a couple of physics courses, energy = 1/2 mass x velocity squared, not just mass times velocity.

mass x velocity is a formula used in idpa and uspsa to determine what they call power factor.

so looking at federal's website for their .40 S&W, American Eagle ammo, the 155 grain at 1160fps gives 463 ft-lbs of energy, while their heavier 180grain at 1000fps gives 400 ft-lbs of energy. so energy drops almost 16%, with velocity dropping just 14% but bullet weight increasing 16%.

i agree that trying to compare, for example, a 9mm vs a .45 isn't as simple as the math above due to differences in guns, weight and balance, etc.

You are correct, Kinetic Energy = 1/2 m x v squared. Momentum = m x v.

Energy is calculated for ballistics for how much "work" the bullet is capable of doing when it hits the target.

2740dmx
02-03-2012, 22:25
I don't know about all these physics and whatnot...:embarassed:

but I do know that: fired from my G27...

165 gr bullets have a much more "snappy" feel than the 180gr variety.

I suppose this means that, for me, the "heavier" projectile is softer recoiling.

I only shoot 180gr out of my .40 cal, for that very reason.

Dave Nowlin
02-03-2012, 22:58
I suspect that if 2 different loads develop the same peak pressure with different burn rates and the same projectile, the percieved recoil will be different. A long slow burn will be perceived more as a push where a fast burn will be percieved as impact. In other words soft recoil as compared to snappy recoil.

3/4Flap
02-04-2012, 08:22
Nuc, so what you are saying is that I am correct, correct?

The question I asked about the BP I actually already gave the answer to; it is the mass of powder and in the case of BP...remember...a high perecentage of it never converts to gas. In fact, a very high percentage compared to many smokeless powders.

What I have been saying, and I'll say again, is that the entire projectile mass must be calculated to determine recoil, not just the bullet weight. However, in service pistols, powder is of minimal impact because of the simple low weights involved, and the total energy generated by the pistols is so low that you get the see-saw effect of some heavy bullet loads recoiling less than some light-bullet loads.

When, as I and several members here have pointed out, you step up to heavier revolver and rifle loads, the relationship between powder and bullet weight becomes patently obvious. But even there, energy developed by a lower bullet weight load may overtake the recoil of a heavier bullet load. Again, projectile mass AND velocity and gun weight must be taken into account.

Other factors impact perceived recoil; grip/stock design, distance of bore line above sights, grip size, and...powder type.

An example of the latter is demonstrated clearly in my Smith 29-9 shooting two loads;

10 grains of Unique under a 240 bullet
18.5 grains of 2400 under a 240 grain bullet

The former FEELS "snappier" {good word by the above members, same I use to describe it} and sharper, and in fact, I developed cysts on tendons in my hand shooting the load even tho it only develops about 1100 fps.

So, what about the other load?

Well, watching the gun shot it is clear, crustal clear, that it is the heavier kicking load, with the gun setting back farther and muzzle rising more, but...

...it is easier on the hand. Yes, you might say, less "perceived" recoil IN SPITE OF ACHIEVING ALMOST THE SAME VELOCITY AS THE UNIQUE LOAD.

As Nuc touched on, likely, no, certainly, the bullet is reaching peak speed farther up the 6 1/2 inch barrel than the Unique load.

For a dramatic example of that process, note the need to use faster powders in the M1 etc semiauto rifle to avoid excessive peak gas port pressures. You may have a load that generates the same velocity using 4895 powder or 4350 powder, but the 4350 is a no-no due to gas port pressures causing excessive battering of the gun action parts in reciprocation.

Back to recoil;

You will see, I am correct in everything I've said here.

1} Total projectile mass {not just "bullet"} must be calculated to determine recoil energy
2} Service pistols like the 9x19 and .40 have such small case capacities that the powder effects recoil very little
3} Due to the maximum velocities obtainable in the stubby 9x19 and .40 cases, the heavier bullet MAY or MAY NOT create the heavier-kicking load. Remember; the actual weight difference between a 155 and 180 GRAIN .40 bullet is not very much. Shoot a 300 grain bullet and a 500 grain bullet from a .45-70, or 240 and 320 from a .44 Mag with similar operating pressures and you see the point, or more accurately, feel it.
4} Generally heavier bullets cause greater recoil as long as the total powder capacity is great enough to allow energies enough to notice {see #3}
5} "Perceived" recoil is a factual, tho indefinable phenomenon, and may vary from shooter to shooter

PS: I am not a Physicist. Just a shooter and handloader for the past 35 years. I've been wrong on numerous occaisions, but not this one.

greenlion
02-04-2012, 09:41
Here is what you actually need to know:

In the SAME gun, and at the SAME velocity, a heavier bullet will recoil more.

In the real world, bullet manufacturers almost always push lighter bullets faster, and that increased velocity adds recoil to the lighter loads. When all is said and done, most of the top defensive loads, whether they are 155gr or 180gr end up recoiling with about the same force, since we tend to push every bullet weight to near its safe limit in velocity. Each of those loads also has its own unique recoil CHARACTERISTIC, which is different from pure recoil AMOUNT. Some help you track your sights better than others in rapid fire. You also can't always believe the published velocity from the manufacturer. Some of the ammo we have tested has been way off the published velocity (like 100fps off !). The solution is... buy a lot of different brands and try them in the same gun side-by-side, and pick the one you like.

NucPhysics
02-04-2012, 10:50
3/4Flap, Looks like pretty much everything you are saying is correct as far as the physics is concerned. The great thing about the physics is it is very logical. In the beginning of this thread, I over simplified it with bullet as the only projectile but it really isn't as you have pointed out. I took out the other variables such as, is the powder fully burnt before the bullet exits the barrel, but am glad you brought it up. It can have an effect.

Greenlion was dead on with this comment "In the SAME gun, and at the SAME velocity, a heavier bullet will recoil more." Obviously because it take a larger charge to move a heavier bullet the same velocity.
In practice, the biggest bullet won't always recoil the most if other factors are altered, depends on the velocity created by the propellant, but all else equal as he states, his statement is completely true.

This discussion usually migrates into a discussion on energy which is what people really get into:

Momentum vs. Energy as in "take down vs lethality", usually a caliber argument but can be a load design discussion, i.e. whats better, a faster light bullet or a heavier slow bullet. This one gets messy as the physics doesn't always seem to match the real world experiences because of the plethora of variables. A gentleman named Anoob (sorry if this name is wrong) did a very good write up some years back discussing this subject.

ron59
02-04-2012, 11:35
Here is what you actually need to know:

In the SAME gun, and at the SAME velocity, a heavier bullet will recoil more.

In the real world, bullet manufacturers almost always push lighter bullets faster, blah blah blah.

Wrong. In the "real world", it's not possible to push the heavier bullet as fast as the smaller bullet.

Look at my example. A TYPICAL 115gr velocity is 1150fps or so. That is NOT fast. It's easy to get over 1200fps with a 115gr bullet. Heck in USPSA *major*, people push a 115gr bullet over 1430fps. No, for a 115gr bullet 1100-1150 is fairly mild.

To push a 147gr bullet that hard? Forget about it. Speer Gold Dot 147gr SD ammo they publish the velocity as 985fps, and I doubt if out of my G17 it would clock that.

On the OPPOSITE side, if you tried to slow a 115gr bullet down to 920fps (what I shoot my 147s at), it likely wouldn't even cycle the slide.

It's a preposterous thing to even say, the fact that you posted it really makes you look foolish.

CDW4ME
02-04-2012, 12:11
Here are some select 40 S&W loads fired from my EMP 40,
Chrono results (average for at least 5 shots):
Remington 180 JHP @ 935 fps / 350# KE / PF 168
Federal 180 JHP @ 944 fps / 356# KE / PF 170
Winchester 180 JHP @ 952 fps / 362# KE / PF 171
Winchester Ranger T 165 @ 1,054 fps / 407# KE / PF 174
Hornady Zombie Max 165 @ 1,078 fps / 426# KE / PF 178

According to the power factor calculation (PF), the 165 gr. loads I tried produce the most recoil.

cole
02-04-2012, 12:23
With factory ammo does the bullet weight have any correlation with the amount of recoil? Example: Does a 155 grain winchester ranger have less recoil than a 180gr winchester ranger?

The math is complicated. Just try this instead: LINK (http://kwk.us/recoil.html). Just use 1lb for the gun, 5-6gr charge weight for lighter bullets (e.g. 124gr, 155/165gr and 185gr) and 4-5gr for heavier ones (e.g. 147, 180 and 230), 4700 as charge fps for faster loads (e.g. 124) and 4000 for slower ones (e.g. 147) and pull velocity from the manufacturer. This is good enough for comparison. If not, enjoy the math.

3/4Flap
02-04-2012, 12:37
Wrong. In the "real world", it's not possible to push the heavier bullet as fast as the smaller bullet.

Look at my example. A TYPICAL 115gr velocity is 1150fps or so. That is NOT fast. It's easy to get over 1200fps with a 115gr bullet. Heck in USPSA *major*, people push a 115gr bullet over 1430fps. No, for a 115gr bullet 1100-1150 is fairly mild.

To push a 147gr bullet that hard? Forget about it. Speer Gold Dot 147gr SD ammo they publish the velocity as 985fps, and I doubt if out of my G17 it would clock that.

On the OPPOSITE side, if you tried to slow a 115gr bullet down to 920fps (what I shoot my 147s at), it likely wouldn't even cycle the slide.

It's a preposterous thing to even say, the fact that you posted it really makes you look foolish.

Why is this forum so well known for jackasses calling the horses mules?

Well, Ron, YOU are wrong.

Take a G20.

Run a 200 grain bullet at 1250 fps.

Run a 155 grain bullet at 1250 fps.

The 200 grain bullet load recoils more.

Period.

Greenlion is correct.

To reiterate; A load using a heavier bullet at the same velocity as a lighter bullet load will recoil more from the same gun.

As for your foolish statement about the light-loaded 115 not properly functioning a RECOIL OPERATED pistol, well...you just proved Greenlion RIGHT, and that would be because IT HAS LESS RECOIL THAN THE HEAVIER BULLET, just as he said.

And yes, factory ammo does, in fact, typically send lighter bullets faster. Is there something wrong with that statement? No. The reasoning has to do with pressures of both, but so what?

And by the way, there are numerous published handloads for the 9x19 that will drive a 147 grain bullet at 1000 fps, and some that will do ditto for the 115. So what if the 115 load is a light load. Which recoils more?

Ron, your entire critique of Greenlion here is complete and total rubbish, made worse by your insults of a person whose post makes sense while yours doesn't.

3/4Flap
02-04-2012, 13:11
Here Ron;

Grabbed from barth's list, just to make it plain. I'll even handicap you the 74 fps.;

9x19 Fed Silvertip |115@1091, 17.9 mv, 304 E|BR 10.1", 0.63", 3.13cu|CL 11.8", 0.58", 3.12cu|avg 3.13, 2.66 re, 1.18

9x19 Win Ranger Talon|147@1017, 21.4 mv, 337 E|BR 13.8", 0.66", 4.70cu|CL 15.5", 0.65", 5.14cu|avg 4.92, 3.77 re, 1.31

Or, so we can put a period at the end of this thing, let's take a gander at this if you don't think you can break 1000 fps with your 147's;

9x19 Fed HydraShok |147@ 935, 19.6 mv, 285 E|BR 13.6", 0.60", 3.85cu|CL 16.1", 0.52", 3.41cu|avg 3.63, 3.19 re, 1.14

Which one has the lower recoil energy, the lighter bullet or the heavier bullet?

tcruse
02-04-2012, 14:38
Another recoil calc application http://www.handloads.com/calc/recoil.asp

Based on my experience this matchs what I expect as I change ammo in G17 Gen 4

NucPhysics
02-04-2012, 14:53
People try pushing a heavier bullet faster and faster with their "hot" loads all the time. We especially see this with people reloading highpowers. I'm not saying they should do this but let's face it, we probably all know someone who does and brags about what their latest concoction is chono-ing at.

However, I will grant you this is not advised for semi-auto handguns. A prime example is I would never want to try to push a 180 gr. bullet in a .40 S&W as fast as a 155 or even a 165 gr. as the extra pressure could lead to a case failure.

ron59
02-04-2012, 14:54
Here Ron;

Grabbed from barth's list, just to make it plain. I'll even handicap you the 74 fps.;

9x19 Fed Silvertip |115@1091, 17.9 mv, 304 E|BR 10.1", 0.63", 3.13cu|CL 11.8", 0.58", 3.12cu|avg 3.13, 2.66 re, 1.18

9x19 Win Ranger Talon|147@1017, 21.4 mv, 337 E|BR 13.8", 0.66", 4.70cu|CL 15.5", 0.65", 5.14cu|avg 4.92, 3.77 re, 1.31

(omitted, don't need to compare these)

Which one has the lower recoil energy, the lighter bullet or the heavier bullet?

In this case, you're comparing a 115gr that is SUPER "soft".
And a 147gr load that is SUPER "hot".

Yes, if you want to compare something like this, then the 147gr bullet would have greater perceived recoil.

1) 1017fps is not 1150fps. 1150fps is typical velocity for a 115gr 9mm round. Here, you've loaded that 147gr bullet pretty hot, and still are nowhere close to a 115gr "typical" load.

2) Go back and read my posts. Comparisons like these are unfair. You are NOT comparing apples-to-apples. You're comparing a super soft 115gr load with a super hot 147gr load.

Just as you are with your 10mm 155gr and 200gr comparison. Sure, you COULD load the 155gr that soft and the 200gr that hot, and yes, the 200gr WOULD recoil more. But I would wager that the vast majority of 155gr loads are not that soft, nor are the vast majority of 200gr loads that hot.

Comparing rounds of the same PF, the heavier bullet recoils less.

My statement about the light 115gr load not cycling the gun is a fair one. Who is going to shoot a load that makes their gun a one shot affair? Pull the trigger, have to rack the slide to eject the case (that wasn't hot enough to cycle the slide), and rack a new round. If you bought factory ammo that did that, would you be happy? As a reloader, when you saw what was going, would you not boost your load? That was the entire point of that argument, was that loading an 115gr bullet down to 920fps is a foolish argument. Or loading a 147gr bullet up to 1150fps (a typical 115gr load) which I don't even believe is possible, is also a FOOLISH ARGUMENT.

Instead of thinking about *real world* loads, and comparing similar (middle of the road) type loadings, you want to look at the extreme outskirts and make what is *technically* correct statements, but at the end of day, comparisons that are indeed silly.

3/4Flap
02-04-2012, 15:08
In this case, you're comparing a 115gr that is SUPER "soft".
And a 147gr load that is SUPER "hot".

Yes, if you want to compare something like this, then the 147gr bullet would have greater perceived recoil.


This IS a technical discussion.

I'll count this above as an apology to Greenlion.

cole
02-04-2012, 22:25
Another recoil calc application http://www.handloads.com/calc/recoil.asp

Based on my experience this matchs what I expect as I change ammo in G17 Gen 4

This calculator works, too, at least for a relative comparison, though it's a bit less refined, and both calculators are less exact than running the actual formula. For the non-reloaders, powder increases the lighter the bullet weight, and lighter bullets are pushed to faster velocities. This presumes the comparison is for optimal defensive loads, not gaming loads. And, compare the numbers in percentages. In the real world, and including my experience, heavier bullets recoil less within caliber comparing optimal defensive loads.

greenlion
02-05-2012, 19:56
I said: Here is what you actually need to know:

In the SAME gun, and at the SAME velocity, a heavier bullet will recoil more.

In the real world, bullet manufacturers almost always push lighter bullets faster.

You said:

Wrong. In the "real world", it's not possible to push the heavier bullet as fast as the smaller bullet.

Look at my example. A TYPICAL 115gr velocity is 1150fps or so. That is NOT fast. It's easy to get over 1200fps with a 115gr bullet. Heck in USPSA *major*, people push a 115gr bullet over 1430fps. No, for a 115gr bullet 1100-1150 is fairly mild.

To push a 147gr bullet that hard? Forget about it. Speer Gold Dot 147gr SD ammo they publish the velocity as 985fps, and I doubt if out of my G17 it would clock that.

On the OPPOSITE side, if you tried to slow a 115gr bullet down to 920fps (what I shoot my 147s at), it likely wouldn't even cycle the slide.

It's a preposterous thing to even say, the fact that you posted it really makes you look foolish.

I'm not wrong..... You can't read..... What I said, and what you posted, have nothing to do with each other.

Before you call someone ELSE a fool, and post it for all to see, you should check and make sure you understand what it is you are objecting to...:wavey:

wanderinwalker
02-06-2012, 21:22
Wait...

Take a .45-70 rifle shooting a 500 grain bullet at 1150 fps using two loads.

One uses 70 grains of Black Powder to accomplish this.

The other uses 22 grains of smokeless.

Recoil energy is greater with the black powder by any measurement, so what is the cause?

I think the difference in the charge weights between black powder and smokeless highlights one of the issues with comparing pistol loads: the charges weights are so small the differences aren't truly significant for comparing recoil.

IMO, at handgun loads and power levels, it's more constructive to be able to infer that a recoil is related to bullet weight in speed. When you're talking .5 gr difference (just a made up number) in powder weight between load A and load B, the .5gr doesn't make as much difference as the velocity difference.

English
02-07-2012, 08:58
BTW, You did better clarify the mass (m) as being the entire projectile - unburnt powder, the wad if present, and anything else ejected forward.

As for the BP example you stated above, I am not positive but I could make a reasonable guess that it could relate to the propellant (BP) still burning and forcing the gun back with added force even though the bullet has exited the barrel, thus the extra kick that you and everyone feels. (Please note this is my best guess based on limited knowledge of BP guns). Whatever the case, all momentum forward still must equal momentum backward.

You are making a consistent error. It does not matter whether the propellant is burnt or unburnt. All that matters is its mass and velocity. What makes it more complicated is that some of that high pressure gas exits the barrel at around 4,000 fps, but that the average speed for the unburnt particles is much lower and in some cases will be lower than the speed of the bullet. In the case of black powder the charge weigh is much greater but the average pressure is lower. Even so, most of it leaves the barrel faster than the bullet and so it makes a big difference to the total momentum.

The loading limit for maximum loads is the pressure spike shortly after the bullet starts to move. To an extent, that follows the gas laws, but, because the rate of burn increases rapidly with temperature, a heavier bullet is restricted to a smaller charge than a lighter bullet because the volume behind it increases more slowly and so the temperature increases more rapidly and that would raise the pressure spike unless the charge was reduced. Hence heavier bullets use less propellant and the total recoil is reduced relative to the lighter bullet and their recooil is reduced relative to what we would expect from bullet momentum alone because there is less "jet" effect.

English

English
02-07-2012, 09:10
I suspect that if 2 different loads develop the same peak pressure with different burn rates and the same projectile, the percieved recoil will be different. A long slow burn will be perceived more as a push where a fast burn will be percieved as impact. In other words soft recoil as compared to snappy recoil.

This is a common error which might apply just a little to a single shot or revolver but does not apply to an auto. In an auto the bullet has left the barrel before the slide has moved an eighth of an inch. So the time it takes a slower or faster bullet to leave the barrel matters not at all because all you can feel at that point is the slight compression of the recoil spring. The momentum transfer is then contained within the momenta of the barrel and the slide. Apart from the impact when the barrel is brought to a stop you feel no more than the recoil spring force pushing the frame backwards until the slide hits its stop. The fact that we don't feel these two impacts separately is a very strong indication that we are not capable of feeling the difference in onset time of the recoil of a revolver with fast or slow loads as opposed to high momentum and low momentum loads.

English

NucPhysics
02-07-2012, 18:20
You are making a consistent error. It does not matter whether the propellant is burnt or unburnt. All that matters is its mass and velocity. What makes it more complicated is that some of that high pressure gas exits the barrel at around 4,000 fps, but that the average speed for the unburnt particles is much lower and in some cases will be lower than the speed of the bullet. In the case of black powder the charge weigh is much greater but the average pressure is lower. Even so, most of it leaves the barrel faster than the bullet and so it makes a big difference to the total momentum.

The loading limit for maximum loads is the pressure spike shortly after the bullet starts to move. To an extent, that follows the gas laws, but, because the rate of burn increases rapidly with temperature, a heavier bullet is restricted to a smaller charge than a lighter bullet because the volume behind it increases more slowly and so the temperature increases more rapidly and that would raise the pressure spike unless the charge was reduced. Hence heavier bullets use less propellant and the total recoil is reduced relative to the lighter bullet and their recooil is reduced relative to what we would expect from bullet momentum alone because there is less "jet" effect.

English

English, when I stated the unburnt powder, I was only acknowledging another poster's input that - yes, it did include unburnt powder. I was not leaving out burnt propellant. That's why I said the below statement which said "and anything else ejected forward" and even underlined "anything". Also, that's why I said projectile and not bullet.

Quote:
Originally Posted by NucPhysics http://glocktalk.com/forums/images/buttons/viewpost.gif (http://www.glocktalk.com/forums/showthread.php?p=18528140#post18528140)
BTW, You did better clarify the mass (m) as being the entire projectile - unburnt powder, the wad if present, and anything else ejected forward.

davsco
02-07-2012, 18:37
You are correct, Kinetic Energy = 1/2 m x v squared. Momentum = m x v.

Energy is calculated for ballistics for how much "work" the bullet is capable of doing when it hits the target.

this thread is about recoil, not terminal ballistics. with the caveat of not having a physics or engineering education, i submit that kinetic energy correlates positively with recoil.

if you look at what the top uspsa production class shooters are using, it's 147g 9mm by far, not 115 or 124. doing the energy calc for those three bullet weights, the 147 (heavier bullet) has the lowest kinetic energy. makes sense as, at least for competition, a low-recoiling gun will allow faster follow up shots.

i'd rather know the correct answer than be right, so i seriously welcome some education on the matter if i am not right.

cowboy1964
02-07-2012, 18:55
deleted

English
02-08-2012, 08:41
this thread is about recoil, not terminal ballistics. with the caveat of not having a physics or engineering education, i submit that kinetic energy correlates positively with recoil.

if you look at what the top uspsa production class shooters are using, it's 147g 9mm by far, not 115 or 124. doing the energy calc for those three bullet weights, the 147 (heavier bullet) has the lowest kinetic energy. makes sense as, at least for competition, a low-recoiling gun will allow faster follow up shots.

i'd rather know the correct answer than be right, so i seriously welcome some education on the matter if i am not right.

The easiest way to think of it might be as a graph. The plot of momentum for a fixed weight bullet would be a straight line angling upwards from the origin. The plot for energy would be like half a parabola rising up and to the right from the origin. Starting from the origin the KE plot is below the momentum plot but it soon crosses it and rises faster and faster. You can say, in this restricted case, that as one increases so the other increases but the fact that they don't increase in the same way makes you idea of positive correlation shaky at best.

If you now plot the energy of a bullet of half the weight on top of the earlier plots it takes longer before it crosses the original momentum plot but then it still races away from momentum. In fact, at twice the speed the lighter bullet will equal the momentum of the heavier bullet but have twice the energy and this, by sensible standards, means that there is not what can be called a positive correlation.

The power factor is an artificial means of equalising the difficulty of making accurate shots with minimum split times. The original idea was that it equalised their stopping power but there is no evidence for this being true. The reason that gamers competing within this regulation choose 147gn 9mms rather than lighter bullets is that the system measures only bullet speed and weight. As lighter bullets of the same momentum need more KE they also use more propellant and the jet effect of that propellant coming out of the barrel adds more to the real recoil than the jet effect from the 147gn. What they want is the easiest to shoot load that meets the regulation and the 147gn does this. This isn't cheating but it is a silly regulation.

English

English
02-08-2012, 08:43
English, when I stated the unburnt powder, I was only acknowledging another poster's input that - yes, it did include unburnt powder. I was not leaving out burnt propellant. That's why I said the below statement which said "and anything else ejected forward" and even underlined "anything". Also, that's why I said projectile and not bullet.

Quote:
Originally Posted by NucPhysics http://glocktalk.com/forums/images/buttons/viewpost.gif (http://www.glocktalk.com/forums/showthread.php?p=18528140#post18528140)
BTW, You did better clarify the mass (m) as being the entire projectile - unburnt powder, the wad if present, and anything else ejected forward.





Accepted with appologies.

English

greenlion
02-09-2012, 19:52
Have you noticed that the original poster hasn't even responded, and yet you all are continuing to write doctoral theses explaining how bullet recoil fits into Einstein's special relativity theory and quantum mechanics?

NucPhysics
02-09-2012, 20:10
Have you noticed that the original poster hasn't even responded, and yet you all are continuing to write doctoral theses explaining how bullet recoil fits into Einstein's special relativity theory and quantum mechanics?


Actually I did notice quite a ways back.

It was a fun ride anyway!! :rofl:

MinnesnowtaWild
02-09-2012, 21:04
The conclusion of this thread is that nobody here really knows.

It's probably different from load to load.

JBP55
02-10-2012, 10:29
The conclusion of this thread is that nobody here really knows.

It's probably different from load to load.


You may not but many of us do. :cool:

cole
02-10-2012, 16:42
The conclusion of this thread is that nobody here really knows. It's probably different from load to load.

You may not but many of us do. :cool:

JBP55 is spot on IMO. It's not that difficult to quantify objective recoil for the purpose of relative comparison. There is a diffference and of course it differs load to load both within and between caliber. That's pretty clear. And, it's quite simpe with tools such as THIS (http://kwk.us/recoil.html) or THIS (http://www.handloads.com/calc/recoil.asp).

Subjective recoil is the unknown. Here, opinion and perspective plays a part. It can differ as much as a person differs from the next. People are big and small, and everything in between. Male and female. Hand size varies. And, much more. None of these have anything to do with shooting experience. One size does not fit all best. That too is pretty clear and easy to understand.

frontier2011
02-11-2012, 10:02
The conclusion of this thread is that nobody here really knows.

It's probably different from load to load.
:agree:TOO many physicist wannabees

MinnesnowtaWild
02-11-2012, 14:30
Okay let me reiterate. The conclusion is this thread is that nobody here really knows, except for a couple of people who think they know based on some recoil formulas.

cole
02-11-2012, 21:05
:agree:TOO many physicist wannabees
:upeyes: Do you really think it takes a physicist to grasp these simple concepts? IMO you need to lower the bar some. Or, maybe I don't think gun owners are stupid as you imply?

Okay let me reiterate. The conclusion is this thread is that nobody here really knows, except for a couple of people who think they know based on some recoil formulas.

:dunno:Umm... we are taking about bullet weight and recoil, and recoil formulas define recoil based on, you guessed it, bullet weight and recoil. I add to this "science" over 50k in 9mm, 40sw and .45acp. What do you offer exactly? Do you have anything to actually contribute? Maybe I'm missing your immaculate wisdom?

NEOH212
02-11-2012, 21:41
3/4Flap,

You are exactly correct, it depends on the gun as the gun needs to be the same. A heavier gun has more inertia (resistance to move) and thus would dampen the felt recoil.

As far as powder charge, primer, crimp, bullet setback, and whatnot, they are irrelavant as the resultant muzzle velocity has already incorporated that into the mechanics.

One thing that isn't accounted for in "felt recoil" is the height of the barrel. Even though the recoil is the same with a higher barrel axis, bore axis, the more torque may make it feel as though there is more recoil even though there isn't. It's merely perception thing.


This is quite possibly the best, most well put explanation on this topic that I have ever read. It backs up what I have been saying for years.

Well said!

:agree: :goodpost:

English
02-12-2012, 04:23
:agree:TOO many physicist wannabees

It does not take much knowledge of physics to explain recoil and is therefore not much of a target for any self respecting physicist wannabee. Apart from the principles of momentum, all that is needed is the branch of applied mathematics known as mechanics. In the UK at least the level needed used to be covered in a pre university maths course. It deals with the forces of ladders leaning against walls, the forces of balls hitting bats and so on.

As a small example consider the implications of muzzle flip. The muzzle flips upwards because of a couple created because the axis of momentum transfer is above the resistance of the hand. A couple is the result of two opposite and equal forces whose parallel axes are separated. The opposite forces cancel with regard to any translation component and all that is left is a pure rotation. In a pistol recoil produces both translation and rotation of course, but we can consider them separately. The rotational force is proportional to the force in one direction multiplied by the perpendicular distance between the parallel axes of the two forces. In practical terms the greater the height of the balrrel axis above the center of pressure on the back strap (which is not the underside of the beaver tail equivalent), the greater the muzzle flip.

I guess that most people know that, but what comes next is more interesting. What the hand has to do to counteract recoil is resist the push to the rear and the rotation upwards. I am neglecting the twist about the barrel axis for simplicity! Suppose that the barrel axis went through the center of pressure of the hand/back strap, even thoough this is not possible with practical self defence type pistols. Then there wouold be no muzzle flip and the recoil would be resisted by simple pressure between hand and back strap. if we now consider the normal case of the barrel axis above the center of pressure we still have to resist the same translational recoil but now have to resist the couple as well. This can only be done with a counter couple provided by the hand pushing forward near the top of the back strap and pulling backwards near the bottom of the front strap. This couple, by definition, exerts no translational effect but because the two forces are equal and opposite the force on the back strap must increase by an amount equal to the opposite force on the front strap.

What this means is that a higher barrel axis does not just increase the muzzle flip, but that the force agains the backstrap is also greater - all other things being equal. Whatever force the shooter has to apply to the front strap to resist muzzle flip has to be added to the force applied to the back strap! Since the force between hand and backstrap is a major component of what is perceived as recoil, a higher barrel axis increases felt recoil.

There is a lot more that can be said, quite scientifically, about felt recoil without recourse to any high level physics but that is probably enough as an example. it is part of why the Glock appear to have less felt recoil than would be expected from its weight.

English

481
02-12-2012, 06:03
This is a common error which might apply just a little to a single shot or revolver but does not apply to an auto. In an auto the bullet has left the barrel before the slide has moved an eighth of an inch. So the time it takes a slower or faster bullet to leave the barrel matters not at all because all you can feel at that point is the slight compression of the recoil spring. The momentum transfer is then contained within the momenta of the barrel and the slide. Apart from the impact when the barrel is brought to a stop you feel no more than the recoil spring force pushing the frame backwards until the slide hits its stop. The fact that we don't feel these two impacts separately is a very strong indication that we are not capable of feeling the difference in onset time of the recoil of a revolver with fast or slow loads as opposed to high momentum and low momentum loads.

English

As usual, the mis-information spouted in your post above suggests that your educational credentials are far below that of what you would have us believe.

There is no such thing as "onset time of the recoil" because the onset of recoil in both revolvers and semiautomatic pistols is an instantaneous event. The transfer of momentum from one object to another is described by Newton's Third Law of Motion which states that, “To every action there is an equal and opposite reaction” and is expressed by the equation


mv = mv


which has no variable for time within its structure. Even to an eighth grade algebra student it is very clear that you are confusing momentum (ρ= mv) with impulse (I = mv/∆t).

As for the onset of recoil in semiautomatic pistols, it too is an instantaneous event since the pistol moves as a single unit and begins to recoil at the exact same instant that the bullet begins to move.
http://i40.photobucket.com/albums/e243/1911Tuner/Gun20Fired.jpg


In the fluoroscope photo above (if you look closely you can see the bones of the firer's hand), the bullet is already in motion and is less than one inch from the muzzle, yet the barrel remains locked to the frame and slide (note the position of the barrel's locking lugs in the upper portion of the slide assembly and the barrel link in the frame just forward and above the trigger) so the gun is recoiling as a single unit, not as two independent sub-assemblies. There is no "onset time of the recoil" in autopistols or revolvers- it is an instantaneous event.

frontier2011
02-12-2012, 14:53
Armchair armorers.

English
02-12-2012, 16:29
As usual, the mis-information spouted in your post above suggests that your educational credentials are far below that of what you would have us believe.

There is no such thing as "onset time of the recoil" because the onset of recoil in both revolvers and semiautomatic pistols is an instantaneous event. The transfer of momentum from one object to another is described by Newton's Third Law of Motion which states that, “To every action there is an equal and opposite reaction” and is expressed by the equation


mv = mv


which has no variable for time within its structure. Even to an eighth grade algebra student it is very clear that you are confusing momentum (ρ= mv) with impulse (I = mv/∆t).

As for the onset of recoil in semiautomatic pistols, it too is an instantaneous event since the pistol moves as a single unit and begins to recoil at the exact same instant that the bullet begins to move.
http://i40.photobucket.com/albums/e243/1911Tuner/Gun20Fired.jpg


In the fluoroscope photo above (if you look closely you can see the bones of the firer's hand), the bullet is already in motion and is less than one inch from the muzzle, yet the barrel remains locked to the frame and slide (note the position of the barrel's locking lugs in the upper portion of the slide assembly and the barrel link in the frame just forward and above the trigger) so the gun is recoiling as a single unit, not as two independent sub-assemblies. There is no "onset time of the recoil" in autopistols or revolvers- it is an instantaneous event.

I keep trying to educate you, but for someone with a degree in physics, another in Russian, an MSc in Organic Chemistry and who is a self proclaimed super genius you show remarkably little apptitude. I will try again.

Most fundamentally you confuse yourself with the fact that there is no time variable within the equation showing, or containing, the conservation of momentum. That is because the equation is limited to the before and after. Even if we consider something as brief as the impact of two steel balls there is a time over which momentum is transmited from one to the other. Any body whose momentum is changed has to be accelerated over some period of time according to the equation acceleration = force/mass. That is, of course only an instantaneous representation of something which in reality, and in the case of the steel balls, happens most usually with a variation in force and hence of acceleration.

If you could film the impact of the balls you would see them deform and spring away from each other as they returned to shape. The transfer of momentum takes place over the whole of the time in which they are in contact. I don't know where you learned your physics but it is obvious that you have learned it like a rather superior parrot rather than like a super genious who would question and make sense of what he was taught.

The above on its own demolishes you whole argument, but let us continue in case you don't understand that.

Momentum transfer is, in one sense, instantaneous as you claim, but it is instantaneous for each vanishingly tiny increment of time. For each instant as the bullet is accelerated along the barrel its change of momentum as its velocity increases has to be equal and opposite to the change in momentum of the mass resisting it. The idea that momentum transfer in the larger sense is instantaneous is a simplifying fiction of physics, like frictionless surfaces, massless springs and non extensible strings. It seems you have never understood the difference between the fiction and the reality and so you parrot this silly idea as though it were true.

Unfortunately for your completely naive argument, the mass to which the equal and opposite momentum is transfered is not even a rigid body in the sense of the steel balls. Let me step you through the sequence of events and the way that momenum is transfered through the pistol and to the shooter.

To start with the barrel and slide are locked together. They have a little play but let us ignore that complication. As soon as the bullet starts moving there is an equal and opposite force applied to the bullet and the barrel/ slide. When the bullet has travelled a 1/4 inch it has some forward momentum and necessarily the barrel/slide must have the same magnitude of rearward momentum. Because the barrel/slide is very much more massive than the bullet its speed is very much less according to mV = Mv. You might note that this representation makes far more sense than your mv = mv which is a trivial tautology. This process continues until the bullet, gas and unburned propellant have left the barrel and for each tiny step along the way as the momentum of the bullet increases, so does the opposite momentum of the barrel/slide. Because the mass of the slide is so much greater than the bullet there is so little movement of the slide that it is not easily peceivable even with high speed photography.

Although some claim that this tiny movement is enough to start the barrel unlocking from the slide, let us assume that it does not quite do so before the bullet and other ejecta have left the barrel and all recoil momentum has been transfered to the gun. In other words the barrel/slide has moved back a little on its rails but the barrel has not started to be cammed down from engagement. At this point we have the interesting situation that the only significant force the barrel/slide can apply to the frame is the extra force of its slight increase of compression of the recoil spring. As you will probably remember, acceleration = force/mass but now the mass we are considering is that of the frame. That small force in the recoil spring transmits a very small amount of momentum between the barrel/slide and the frame. The barrel/slide slows just a little and the frame gains just a little rearward velocity.

At this point almost all the recoil momentum is still contained by the slide/frame, but that is about to change abruptly as the barrel is decelerated to a halt relative to the frame in a distance of about 1/4 inch. That takes quite a lot of force and so it transfers quite a proportion, a little more than the ratio of barrel mass to slide mass, of the recoil momentum to the frame. The slide then continues for another 1.75 inches or so and during that time, apart from some friction, the force it exerts on the frame if only the force exerted by the recoil spring and so the work done against the mass of the frame is only the same as the work the shooter would do in retracting the slide. This slows the slide a little more and increases the rearward velocity of the frame a little, but not all that much. We can all rack the slide without thinking of it in terms of recoil.

But then we come to the dramatic bit. The slide, still travelling quite quickly, is brought to a halt by its impact with the frame within less than a 1/16th of an inch. This results in very high forces as the distance of decelleration is less than for the barrel and because the slide is a lot heavier than the barrel. Relative to the time that the bullet was in the barrel this has all been a very slow motion sequence. If we neglect the swapping of momentum between frame and slide/barrel as the recoil spring accellerates it forwards we could finally say that the description of the transfer of momentum is now complete. But, of course it isn't.

The reason it isn't is that the mass resisting the recoil is not only the pistol but the hand, arm and body of the shooter. No matter how strong and hard handed the shooter might be, recoil drives the pistol back into the shooter's hand and so we have another transfer of momentum delayed by time as the hand first offers little resistance and then rapidly more as the flesh is compressed. I will leave you to work through the details of this transfer along the lines previously defined.

Transfer of momentum is NOT instantaneous and CANNOT be instantaneous but in a pistol the major pulses of transmission are spread far apart in time relative to the time it takes the bullet to leave the barrel. In human terms that long time is very short and we don't feel two jolts of momentum transfer.

In a revolver, all of that bullet momentum is transfered to the whole gun in the time it takes the bullet to leave the barrel. That time is extremely short relative to the time it take the auto pistol to finnish its transmission to the frame and so it is most unlikely that we can tell the difference between the recoil of a slow heavy bullet and a fast light one if the momenta of the two ejecti are the same. Once again, the transfer of momentum to the hand takes a lot longer than the time the bullet takes to leave the barrel.

Your problem is that you have an eidetic memory. As a result you remember everything and understand nothing. All the way through school your memory has gained you good marks and then through to graduation it did quite well for you. Why should you bother to learn to think when you could remember all the answers? And so when you should have been learnig to use your intelligence it was too easy and then it was too late. So now you are a middle aged man who can't understand momentum transfer as well as a competent well educated 18 year old.

You might not like this description and that is understandable, but it is your self description that means either that you think you can get away with lying because it is the internet, or that my analysis is correct. If you are a super genius you have to be able to solve the difficult but simple problems of IQ tests and do so quickly. If you have a physics degree you have failed to apply that intelligence to understanding even the simple levels of physics and have accepted the simplicity of equations without understanding their obvious limits. There are only two explanations for that. Either you do not have the physics degree you claim or you have been able to pass your exams without understanding what you were being taught. The only way to do that is by the good fortune, or handicap, of a brilliant memory. Do feel free to give us a counter explanation.

English

481
02-12-2012, 21:38
Do feel free to give us a counter explanation.

English

Engli' -

Sure.

Your frequent and unnecessarily lengthy responses suggest that you are a lonely codger living out what little remains of your time in a small, dowdy flat, who, having only his hand for company, beats this outlet just as endlessly for what little social gratification it offers to someone who hasn't the ability to relate directly to people simply for the annoyance that he brings with him that drives all of them away.

When called to prove your claimed abilities (such as being able to predict time-to-incapacitation in another thread) you respond with a tantrum :rant: (fueled by an impressive persecution complex) that usually runs at least several hundred words and is filled with all sorts of misspellings and errors and rapidly degenerates into senseless babbling very quickly. Your most recent post is a good example of such an occurrence.

Everything that you post reads like that of someone who has never actually fired a handgun. (AirSoft™ doesn't count :shame:) It appears that you have only what you have been told by others about what it is like to fire a handgun to rely upon for all your claimed expertise in the topic.

Here...

Momentum transfer is, in one sense, instantaneous as you claim, but it is instantaneous for each vanishingly tiny increment of time. For each instant as the bullet is accelerated along the barrel its change of momentum as its velocity increases has to be equal and opposite to the change in momentum of the mass resisting it.

...you prove my point by describing impulse, I = mv/∆t, confusing it for the instantaneous impingement of momentum upon an object and proving that there is no "onset time of the recoil". For someone claiming to have a degree in "the maths", your conspicuous ignorance of the simple algebraic expression for impulse (I = mv/∆t) suggests that your degree, if you actually graduated from high school which seems more unlikely with each of your passing rants, is more likely in one of the textile arts- like basket-weaving, leathercraft or creative pottery art.

In light of all this, it is not possible to take any of your endless pontifications seriously or without laughter. :animlol:

frontier2011
02-12-2012, 22:41
:yourock::wave:

English
02-13-2012, 09:52
.....
When called to prove your claimed abilities (such as being able to predict time-to-incapacitation in another thread) ....

.....

I note that you are still repeating this ridiculous lie even though this post does, I think, contain only the one. If you lie about such trivial matters, how do you expect anyone to believe your claims about your education?

English

Zombie Steve
02-13-2012, 10:24
I'd invite anyone to come shoot some 150's and 180 grain bullets from my .30-06 bolt gun. Heck, I could even tweak the loads so they're going the same speed with the same powder, but it's not necessary to illustrate the point.

It's a fairly light rifle with no butt pad. You can shoot the 150's all day (2,750fps). You'll get sick of the 180's in short order, and they're only going 2,600 fps. No slide, no springs, you're just taking it on the shoulder.

cole
02-14-2012, 00:30
I'd invite anyone to come shoot some 150's and 180 grain bullets from my .30-06 bolt gun. Heck, I could even tweak the loads so they're going the same speed with the same powder, but it's not necessary to illustrate the point.

It's a fairly light rifle with no butt pad. You can shoot the 150's all day (2,750fps). You'll get sick of the 180's in short order, and they're only going 2,600 fps. No slide, no springs, you're just taking it on the shoulder.

Naturally, as the 180gr has ~15% more free recoil energy. THIS (http://www.handloads.com/calc/recoil.asp) with THIS (http://www.reloadammo.com/3006load.htm) explains that. However, the same (i.e. heavier bullet = more free recoil energy) does not apply comparing service handguns with factory defensive loads. Compare a 124gr 9mm at 1250fps vs. a 147gr 9mm at 950fps and you're talking >20% more free recoil energy with the 124gr. That will be noticeable.

English
02-14-2012, 08:45
...
As for the onset of recoil in semiautomatic pistols, it too is an instantaneous event since the pistol moves as a single unit and begins to recoil at the exact same instant that the bullet begins to move.
http://i40.photobucket.com/albums/e243/1911Tuner/Gun20Fired.jpg


In the fluoroscope photo above (if you look closely you can see the bones of the firer's hand), the bullet is already in motion and is less than one inch from the muzzle, yet the barrel remains locked to the frame and slide (note the position of the barrel's locking lugs in the upper portion of the slide assembly and the barrel link in the frame just forward and above the trigger) so the gun is recoiling as a single unit, not as two independent sub-assemblies. There is no "onset time of the recoil" in autopistols or revolvers- it is an instantaneous event.

As you persist with your ridiculous misunderstanding of the recoil effects in an auto pistol, let us try to make some progress.

Let us assume you are firing a Glock and that the mass of the slide is a little greater than the combined mass of the barrel and frame. At the moment when the slide is half way back, do you dispute that the rearward momentum of the slide is greater than that of the frame and barrel in combination? That is, the slide is moving backwards faster than the frame/barrel and it is heavier.

This is a simple question but its answer shows what nonsense you are promoting as a scientific position.

English

481
02-14-2012, 10:37
As you persist with your ridiculous misunderstanding of the recoil effects in an auto pistol, let us try to make some progress.

Let us assume you are firing a Glock and that the mass of the slide is a little greater than the combined mass of the barrel and frame. At the moment when the slide is half way back, do you dispute that the rearward momentum of the slide is greater than that of the frame and barrel in combination? That is, the slide is moving backwards faster than the frame/barrel and it is heavier.

This is a simple question but its answer shows what nonsense you are promoting as a scientific position.

English

This little bit of nonsensical drivel (treating the slide as a subsystem that is independent of the pistol) proves beyond any doubt that you are absolutely clueless about the mechanics involved in a recoiling system.

There is a reason that you have so many difficulties here (with so many GT members) and this little bit of pompousity is a fine example of the specific personal quality (it also confirms your well-known reputation across the gun forums) that many here find so repugnant. It is also why I (and so many others here) have never seen fit to extend to you the offering of friendly, legitimate discourse or debate and never will.

Now you have all of the answers.

English
02-14-2012, 10:57
This little bit of nonsensical drivel (treating the slide as a subsystem that is independent of the pistol) proves beyond any doubt that you are absolutely clueless about the mechanics involved in a recoiling system.

There is a reason that you have so many difficulties here (with so many GT members) and this little bit of pompousity is a fine example of the specific personal quality (it also confirms your well-known reputation across the gun forums) that many here find so repugnant. It is also why I (and so many others here) have never seen fit to extend to you the offering of friendly, legitimate discourse or debate and never will.

Now you have all of the answers.

The translatioon of that piece of rubbish is that you can't answer without admitting that you are talking rubbish. The application of your intellect is limited to abuse.

There are, by the way, plenty of pompous oiks like you on the internet who are supported by other oiks. There are also plenty of intelligent people who support me and several write and tell me so.

English

English

English

481
02-14-2012, 11:48
The translatioon of that piece of rubbish is that you can't answer without admitting that you are talking rubbish. The application of your intellect is limited to abuse.

There are, by the way, plenty of pompous oiks like you on the internet who are supported by other oiks. There are also plenty of intelligent people who support me and several write and tell me so.

English

English

English


Classic.


There are also plenty of intelligent people who support me and several write and tell me so.


Yeah, you're a real superstar. :upeyes:





English

English

English


Are you letting your other personalities "sign off" on your posts now?

English
02-15-2012, 07:01
For those who have been following the rational side of this discussion, let us continue.

When the slide of the Glock pistol is half way back in recoil it is still moving quickly and so it has more rearward momentum than the frame. After it has moved another half inch the slide will have been slowed by the energy absorbed by the recoil spring and friction. The same forces that slowed it will have acted in the other direction to speed up the rearward motion of the frame. As a direct consequence the slide will have lost rearward momentum and the frame will have gained rearward momentum. Thereby, any moderately rational person can see that the auto pistol does not recoil as a unit and that momentum is transfered from one moving part to another which has an appropriate single degree of relative freedom constrained by a spring.

To those who might be interested in 481's mental state as he continues to deny simple reasoning you might note that the depth of his counter analysis contains really important things like the suggestion that I m*********, spell badly and on one occasion signed myself three times by accident. Wow! That is just so upsetting! I stay awake at nights wondering what new forms of abuse he will dream up next that will make him look even more stupid.

English

JBP55
02-15-2012, 07:47
Just the opposite. In the same type ammunition the heavier round is slightly softer shooting and will impact slightly higher on target compared to the lighter round.

I gave the correct answer in post 2. :yawn:

English
02-15-2012, 11:36
I gave the correct answer in post 2. :yawn:

I am not denying it but it would help some people if you explained why that is.

English

marvin
02-16-2012, 17:25
http://i40.photobucket.com/albums/e243/1911Tuner/Gun20Fired.jpg


.

just wanted to say thanks for posting this photo. it's just too cool

marvin
02-16-2012, 17:47
I'm not buying any of this.

I'm a competition shooter and reloader. USPSA 'B' shooter and missed Expert in IDPA by less than a half-second last year, I expect to easily make it this year.

In "the games" (IDPA/USPSA), they compare bullet weights by using a computation called Power Factor. That is bullet weight times velocity.

They will usually then declare a minimum Power Factor that can be made, such as 125,000 (often called 125PF). For example, a 115gr 9mm bullet traveling 1150fps has a power factor of 132,250 (or abbreviated 132PF). That's pretty close to WWB 115gr 9mm FMJ bullet.

I shoot 147gr bullets, loaded to a similar PF. I load them to achieve velocity of around 915fps for a PF of 134PF.

The result? The 147gr round has a MUCH softer recoil than the 115gr bullet.

I have done this "test" with multiple friends, all who have done it have agreed with me. Take a magazine and load it with 10 rounds, 5 of 115gr WWB and 5 of my 147gr reload. Alternate them so you'll fire one first, then the other. The "softness" of the 147gr will put a smile on your face.

Some people's reaction is "you're comparing a HOT 115gr to a SOFT 147gr round". And I would disagree with that. The 115gr WWB round is by no means hot. And there is no way a 147grainer at 915fps could be considered soft. I think Speer Gold Dot 147grain bullets only reach 950fps or so out of a G17 sized gun (the size these comparisons and measurements were made through). 915fps is not *that* far off of 915fps.... not considering when I COULD load it way down to 850fps and still (almost) make minimum power factor.

I would suspect that these same results would be seen for any round, whether it is .40 or .45ACP.

I have converted several of my gaming reloading friends to shooting 147gr bullets just because of this. It is not hearsay, it is not myth, but fact. I have a chrono and chrono all my loads, as well as some factory loads for comparison sake.

Talk about pressures, talk about barrels, etc has no bearing. As long as your pressures are safe and you use the same barrel to compare, those points are moot. So are pretty much any other piece of "evidence" listed above.

Use ONE gun (the same gun). Take a lighter round and a heavier round of the same PF and shoot them through it, alternating as I described above. Money says the heavier round will feel softer.


as a USPSA "A" class limited shooter and a reloader. recoil still comes down to how it feels to you.

while the 147 load seems softer to some, to me it feels slow and mushy with more muzzle flip. i much prefer the snapper but with less muzzle flip of the 115's.

i think that more shooters use 147's more for the way it takes down pepper poppers, than for the way it recoils.

481
02-16-2012, 19:48
http://i40.photobucket.com/albums/e243/1911Tuner/Gun20Fired.jpg (http://i40.photobucket.com/albums/e243/1911Tuner/Gun20Fired.jpg)

just wanted to say thanks for posting this photo. it's just too cool

You're welcome, marvin, and I agree, it is a very cool picture.

What's really interesting about the fluorograph is that it shows that while the base of the bullet (which is about 0.85 inch from the muzzle assuming that it is a 230 gr. FMJRN; 230 gr. FMJRNs are about 0.66" in length) will clear the last edge of the muzzle/rifling in less than 1/10,000th of a second (assuming that the bullet is moving at 825 - 850 fps at that point in the barrel), the barrel's locking lugs have not yet disengaged from their recesses located within the underside of the 1911's slide.

The slide remains locked in battery (with no additional compression of the spring) despite the fact that the bullet is less than 1/10,000th of a second from departing from the barrel and since recoil commences at the instant that the bullet moves forward the entire pistol recoils instantaneously as a single unit.

Despite the fact that it's only a still photo, it is an excellent illustration of semiautomatic pistol function.

English
02-17-2012, 06:48
You're welcome, marvin, and I agree, it is a very cool picture.

What's really interesting about the fluorograph is that it shows that while the base of the bullet (which is about 0.85 inch from the muzzle assuming that it is a 230 gr. FMJRN; 230 gr. FMJRNs are about 0.66" in length) will clear the last edge of the muzzle/rifling in less than 1/10,000th of a second (assuming that the bullet is moving at 825 - 850 fps at that point in the barrel), the barrel's locking lugs have not yet disengaged from their recesses located within the underside of the 1911's slide.

The slide remains locked in battery (with no additional compression of the spring) despite the fact that the bullet is less than 1/10,000th of a second from departing from the barrel and since recoil commences at the instant that the bullet moves forward the entire pistol recoils instantaneously as a single unit.

Despite the fact that it's only a still photo, it is an excellent illustration of semiautomatic pistol function.

Your DQ, that is your dumbness quotient for those who have not studied psychology, is quite remarkable. You KNOW three things which you are ignoring.

The first thing you KNOW is that the slide and barel are locked together for only the first part of their movement and that neither is locked to the frame although constrained to one degree of freedom relative to it.

The second thing you KNOW is that the slide slides back on the frame at a speed too difficult to follow by eye and therefore it has gained that speed relative to the frame by the time the bullet has left the barrel.

The third thing you KNOW is that the average speed of the bullet as it travels the length of the barrel is about 550 feet per second. For a 5" barrel that means a bullet travel of about 4.5 inches and a time in barrel of about 7/10,000 of a second. The mass of the slide and barrel of a 1911 Gvt is about 17oz and the mass of a 230gn bullet is 230/7000 oz. So the initial speed of the slide and barrel is about 230/(7000x17) of the speed of the bullet as it leaves the barrel at about 800 fps. That is, the initial slide velocity is about 1.5fps and it travels backwards for about 1.75 inches in a bit less than a fifth of a second. More importantly it travels less than 1.5x12x7/10000 or 0.0126 of an inch in the time it takes the bullet to leave the barrel. Why is it less? because the slide and barrel have been gaining speed as the bullet has travelled along the barrel and so its average speed is probably about 2/3rds its final speed so we can say it travels 8 thousandths of an inch by the time the bullet leaves the barrel. Do you think you or anyone else can see a movement of 8 thous on a flouroscope picture?

Now, I have used my model of the slide and barrel recoiling semi independently of the frame, but by all means re-do the calculation including the mass of the frame as part of the instantaneous unitary recoil of the gun. It only makes the conclusion worse for your model!

You might not have done the actual calculation of slide velocity but I credit you with the ability to do the simple maths involved. That apart, you KNOW all the facts above and yet you are dumb enough to keep repeating your claim about instantaneous recoil in the hope that lots of other dumb people will believe you.

English

3/4Flap
02-17-2012, 07:21
If the locking lugs on that 1911 barrel bottomed out in their recesses BEFORE firing {no way to be sure from that picture}, the gap above them should be measured to see how it coincides with English's estimate of .008" movement of the barrel back.

Now, not to mess up a good fight with a serious question, but I am curious as to how the reconstructions so far submitted would apply to the TT33 Tokarev, a sort of opposite specimen from the Glock.

The TT33 has a light slide and a fast moving bullet. Say 86 grain bullet at 1450 fps for an average estimate.

Many surplus TT33's show signs of serious primer swipe unless a new, stronger recoil spring is installed. The common belief is that the breech is opening before internal pressures have dropped to zero.

Anybody care to have a go at that?

I don't have an opinion or knowledge about the actual reasons for this, but am, rather, interested in what some of you think. I know the fix for the TT33 issue, but the technical details I cannot comment on with knowledge.

481
02-17-2012, 11:32
Your DQ, that is your dumbness quotient for those who have not studied psychology, is quite remarkable. You KNOW three things which you are ignoring.

The first thing you KNOW is that the slide and barel are locked together for only the first part of their movement and that neither is locked to the frame although constrained to one degree of freedom relative to it.

The second thing you KNOW is that the slide slides back on the frame at a speed too difficult to follow by eye and therefore it has gained that speed relative to the frame by the time the bullet has left the barrel.

The third thing you KNOW is that the average speed of the bullet as it travels the length of the barrel is about 550 feet per second. For a 5" barrel that means a bullet travel of about 4.5 inches and a time in barrel of about 7/10,000 of a second. The mass of the slide and barrel of a 1911 Gvt is about 17oz and the mass of a 230gn bullet is 230/7000 oz. So the initial speed of the slide and barrel is about 230/(7000x17) of the speed of the bullet as it leaves the barrel at about 800 fps. That is, the initial slide velocity is about 1.5fps and it travels backwards for about 1.75 inches in a bit less than a fifth of a second. More importantly it travels less than 1.5x12x7/10000 or 0.0126 of an inch in the time it takes the bullet to leave the barrel. Why is it less? because the slide and barrel have been gaining speed as the bullet has travelled along the barrel and so its average speed is probably about 2/3rds its final speed so we can say it travels 8 thousandths of an inch by the time the bullet leaves the barrel. Do you think you or anyone else can see a movement of 8 thous on a flouroscope picture?

Now, I have used my model of the slide and barrel recoiling semi independently of the frame, but by all means re-do the calculation including the mass of the frame as part of the instantaneous unitary recoil of the gun. It only makes the conclusion worse for your model!

You might not have done the actual calculation of slide velocity but I credit you with the ability to do the simple maths involved. That apart, you KNOW all the facts above and yet you are dumb enough to keep repeating your claim about instantaneous recoil in the hope that lots of other dumb people will believe you.

English

English, English and English,

Still sore, huh? :yawn:

Are all of your three personalities bitter little disarmed British subjects :rant: or is it just the one who wrote the seething post above?

If I were to elect to debate such inanity (your mindless ignorance of photographic evidence that confirms slide position in relation to projectile position) how would I know that I am addressing the proper personality? From the pathetic and misapplied "maths" (yours is a hilarious, backward term) above, it appears that not one of the three of you :crazy: has a degree of any sort.

I doubt that anyone takes seriously the deranged musings of an armchair expert (you've stated that you've never served in the military or police) especially those of one who has never actually fired a handgun himself. (AirSoft™ doesn't count)

English
02-18-2012, 07:18
Are all of your three personalities bitter little disarmed British subjects :rant: or is it just the one who wrote the seething post above?
I susoect it is not just me that sees no connection between my post and the disgusting state of British fireams legisltation. All I did was point out your stupidity in being unable to reconcile obvious facts with some strange distortion of a what you believe to be a theory about recoil. Even though I made it very simple for you, you are clearly still stuck in that mental swamp.

From the pathetic and misapplied "maths" (yours is a hilarious, backward term) above, it appears that not one of the three of you :crazy: has a degree of any sort.
US culture and UK culture use different words for the same thing. If you think the term "maths" is backward or hilarious, you merely display your cultural ignorance.

More importantly the mathematics I used was barely more than arithmetic so for someone of your intellectual powers it would be easy to point out any errors. I have never claimed infallibility but strangely enough no one has made detailed attacks on my maths. Others might wonder why you have not taken that simple step, but I don't.
I doubt that anyone takes seriously the deranged musings of an armchair expert (you've stated that you've never served in the military or police) especially those of one who has never actually fired a handgun himself. (AirSoft™ doesn't count)
I have answered this nonsense before but a membership of military or police has no bearing on the ability to understand the physics of recoil as you demonstrate so well. By the way, why did you resign from the police?

Apart from that, I own about 15 handguns of which 3 are revolvers. My round cound for 10mm is well over 20,000. Others, I have not estimated. This is obviously a low number in comparisson to a red blooded free citizen liar such as you, but it is a long way from airsoft. I do have airsoft and pellet pistols as well but they don't much interest me.

Do you knows the first rule of holes? When you are in a hole you can't get out of, stop digging and start thinking. Your talent for self humiliation is quite remarkable.

English

3/4Flap
02-18-2012, 07:54
Hey, can you two pull your thumbs out of each other's eyes for a minute and have a go at answering my questions?

Citizen or Subject doesn't matter to me.

Just curious what you think.

481
02-18-2012, 14:45
I susoect it is not just me that sees no connection between my post and the disgusting state of British fireams legisltation. All I did was point out your stupidity in being unable to reconcile obvious facts with some strange distortion of a what you believe to be a theory about recoil. Even though I made it very simple for you, you are clearly still stuck in that mental swamp.

US culture and UK culture use different words for the same thing. If you think the term "maths" is backward or hilarious, you merely display your cultural ignorance.

More importantly the mathematics I used was barely more than arithmetic so for someone of your intellectual powers it would be easy to point out any errors. I have never claimed infallibility but strangely enough no one has made detailed attacks on my maths. Others might wonder why you have not taken that simple step, but I don't.

I have answered this nonsense before but a membership of military or police has no bearing on the ability to understand the physics of recoil as you demonstrate so well. By the way, why did you resign from the police?

Apart from that, I own about 15 handguns of which 3 are revolvers. My round cound for 10mm is well over 20,000. Others, I have not estimated. This is obviously a low number in comparisson to a red blooded free citizen liar such as you, but it is a long way from airsoft. I do have airsoft and pellet pistols as well but they don't much interest me.

Do you knows the first rule of holes? When you are in a hole you can't get out of, stop digging and start thinking. Your talent for self humiliation is quite remarkable.

English

English, English and English,

Oh, are these the imaginary handguns that you claim to own that are "kept" in another country? I suppose that they are stored at your imaginary chalet in the Swiss Alps? :crazy:

What do you do when one of your personalities wants to shoot but the other two don't want to? :rofl:

English
02-19-2012, 07:14
English, English and English,

Oh, are these the imaginary handguns that you claim to own that are "kept" in another country? I suppose that they are stored at your imaginary chalet in the Swiss Alps? :crazy:

What do you do when one of your personalities wants to shoot but the other two don't want to? :rofl:

My chalet is not imaginary - I just don't have one.

My handguns are just stored at a range in a locker like those of other Brits. Of course, I have to be super rich just to travel to Switzerland. It is 600 miles and that is further than from Dallas to Houston. It would be very tiring to go for an afternoon so I go for about 10 days at a time.

Can you dredge up anything even more stupid to say from you unimaginative mind?

English

English
02-19-2012, 07:37
If the locking lugs on that 1911 barrel bottomed out in their recesses BEFORE firing {no way to be sure from that picture}, the gap above them should be measured to see how it coincides with English's estimate of .008" movement of the barrel back.

Now, not to mess up a good fight with a serious question, but I am curious as to how the reconstructions so far submitted would apply to the TT33 Tokarev, a sort of opposite specimen from the Glock.

The TT33 has a light slide and a fast moving bullet. Say 86 grain bullet at 1450 fps for an average estimate.

Many surplus TT33's show signs of serious primer swipe unless a new, stronger recoil spring is installed. The common belief is that the breech is opening before internal pressures have dropped to zero.

Anybody care to have a go at that?

I don't have an opinion or knowledge about the actual reasons for this, but am, rather, interested in what some of you think. I know the fix for the TT33 issue, but the technical details I cannot comment on with knowledge.

Thanks for reminding me. If we compare the momentum of the Tokarev bullet with a 125gn 9mm at 1150fps, 86x1450/125x1150 = .86. So the recoil momentum is probably about 88% that of the 9mm if we allow for what is probably a higher gas pressure as the bullet exits the barrel. I don't know the mass of the toarev slide and barrel but it could be 88% of the mass of a comparative 9mm and still have the same slide speed. The calculation that gave me about 8 thou movement befor the bullet let the barrel was based on a 1911 Gvt with considerabley more bullet momentum but as the Tok bullet is travelling a lot facter and as the 1911 slide is relatively light, I would think that it would take less time for the bullet to clear the barrel and so there would be less slide movement and less drop at the breech than for a 1911.

If we guess at 5 thou movement backwards, that would give us about 3 thou downwards and you would not see that as firing pin smear on the primer. The cause has to be that the firing pin is not returning quickly enough, for whatever reason, and the swipe effect is taking place long after the bullet has left the barrel, like up to 0.1 or 0.2 inches of barrel movement! (not calculated , just guessed as I am being called away.

English

3/4Flap
02-19-2012, 08:00
Thanks for reminding me. If we compare the momentum of the Tokarev bullet with a 125gn 9mm at 1150fps, 86x1450/125x1150 = .86. So the recoil momentum is probably about 88% that of the 9mm if we allow for what is probably a higher gas pressure as the bullet exits the barrel. I don't know the mass of the toarev slide and barrel but it could be 88% of the mass of a comparative 9mm and still have the same slide speed. The calculation that gave me about 8 thou movement befor the bullet let the barrel was based on a 1911 Gvt with considerabley more bullet momentum but as the Tok bullet is travelling a lot facter and as the 1911 slide is relatively light, I would think that it would take less time for the bullet to clear the barrel and so there would be less slide movement and less drop at the breech than for a 1911.

I see the point you are trying to make here and you could be right, but if you observe ejection patterns of the TT33 pistols, you find empties being tossed much, much farther than empties from 9x19 pistols. Ditto for the CZ52's. So SOMETHING is going on to cause that, and the accepted "wisdom" is that something is slide speed. It would be easy to weigh the slide and make certain of some of your estimations. I don't own a TT33 anymore.

I think the best method to determine the answer to the visual drop in the 1911 barrel would require handling of the actual pistol pictured to determine if the lugs bottom out when the pistol is in battery. That would verify or disprove your calculations.

If we guess at 5 thou movement backwards, that would give us about 3 thou downwards and you would not see that as firing pin smear on the primer. The cause has to be that the firing pin is not returning quickly enough, for whatever reason, and the swipe effect is taking place long after the bullet has left the barrel, like up to 0.1 or 0.2 inches of barrel movement! (not calculated , just guessed as I am being called away.

I don't think there is any doubt that the completion of the primer swipe is taking place after the bullet leaves the barrel. I guess the real question is how much if any, barrel/slide movement is occuring with the bullet in the barrel. I personally do not know if barrel pressure drop to zero immediately when the base of the bullet clears the muzzle or some little distance beyond that.

All of this is more or less unnecessary conjecture because we know the fix...stiffer recoil spring...
English

Thanks.

481
02-19-2012, 21:04
Aww, such anger. :shame:


Can you dredge up anything even more stupid to say from you unimaginative mind?

English


Dance, clown. Dance.

:cool:

English
02-20-2012, 04:58
Aww, such anger. :shame:




Dance, clown. Dance.

:cool:

I knew you could do it if you tried. Congratulations on an even more inane post.

Did you think of answering 3/4Flap's post with your fallacioous model?

English