Talking sub-compact ballistics [Archive] - Glock Talk

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LEAD
01-30-2010, 12:19
When considering sub-compact barrrel lengths, do some rounds start to look better or worse than others. For example, since there is less barrel to burn up the powder, do the merits of a .357sig over a 9mm become lost as less time is allowed for the powder to burn.

When using a sub-compact platform do lighter faster bullets or slower heavier bullets gain any more of an edge.

Sorry if this is a repeat, but I couldn't find conclusive info on it.

fredj338
01-30-2010, 13:20
Typically, the faster & smaller the bullet, the faster it loses vel. in shorter bbls. You never get to the point where a 9mm is the same as a 357sig for example, but muzzle blast & flash will start being a problem w/ high vel rounds in shorter tubes.

LEAD
01-30-2010, 15:17
So would you think that a 40 would become more lucrative than a .357sig in the g27/33 platform?

Also would you think it would be better to use something heavier in the chosen caliber, like a 180gr 40S&W Vs. a 135Gr 40, and a 147gr Vs. a 115gr 9mm?

fredj338
01-30-2010, 16:37
It depends. Most of the JHP today will still expand well minus 100fps. There is a trend to use +P ammo to keep vel. up in the 45acp, but it only adds recoil. Same w/ say the 40 & a 155grJHP. The vel is much higher than a 180gr but recoil goes up in the smaller guns. It's kind of a balancing act. In the 9mm, I go 124gr+P, recoil is just not an issue. In the 40, I go 165gr, in the 45, I will drop to a 200grXTP or 185grWSTHP. There is no real magic choice. SOme guys will stay w/ the heaviest bullet available regardless of vel. to insure deepest penetration.

Steel Head
01-30-2010, 17:04
In almost all data I've found the heavier for caliber(230/45-180/40-147/9) bullets loose less fps per inch of barrel than the lighter offerings
The trend continues-the lighter the bullet the bigger the loss

DEADEYEGUY
01-30-2010, 17:20
Most .45 loads are tested in 5" barrels. They are big slow rounds to begin with. Go to a 3" barrel you are losing alot of of velocity. Most 9mm's and .40's are tested in 4" barrels and are high presure rounds. Going to a 3"-3.5" barrel affects performance very little.

ricklee4570
01-30-2010, 19:55
Interesting topic. Isn't there some rounds made by Speer specifically designed for the Subcompacts?

Molon
01-30-2010, 20:34
Interesting topic. Isn't there some rounds made by Speer specifically designed for the Subcompacts?

Speer Short Barrel (SB)



http://www.box.net/shared/static/5li8m192c0.jpg

Scott in Houston
01-30-2010, 21:51
I love my new G32 and now want a G33, but am starting to think I shouldn't bother. My G27 is likely more effective for its caliber than the G33... from what I'm reading.

I own a G27 and G26.

Mrs_Esterhouse
01-30-2010, 22:48
Enjoy...

Scott in Houston
01-30-2010, 23:55
Thanks! Interesting .357 stats. Now it looks like the 357 SIG is a very good performer with shorter barrel lengths.

fredj338
01-31-2010, 00:23
Most .45 loads are tested in 5" barrels. They are big slow rounds to begin with. Go to a 3" barrel you are losing alot of of velocity. Most 9mm's and .40's are tested in 4" barrels and are high presure rounds. Going to a 3"-3.5" barrel affects performance very little.
Not really. The bore dia/gas expansion ratio plays a big part. Rem 230grGS go 825fps form my 5" 1911 & 775fp s from the 3.5" 1911OM, not much vel loss. The Speer 125grGDHP in a 5" 357sig makes 1380fps & only 1300fps in my 3.5" P239. Smaller bore, highe vel/pressure rounds will lose vel faster/inch. Some true testing data. http://www.ballisticsbytheinch.com/9mmluger.html

Steel Head
01-31-2010, 00:54
Almost all-------I do think the 357SIG is a great choice in short barrels

Darkangel1846
01-31-2010, 13:14
In self defense ammo I don't see any big difference at self defense distances. At up to 25 yards I see nothing to be overly concerned about, except maybe in small cal handguns but maybe there is and I just don't get it. The difference in speeds and self defense distances offer me little concern in most ammos. Now shooting at one hundred yards , yeah, then I might take some consideration into bullet weight and speed, but not at self defense distances.
Am I wrong here?

glocksterr
01-31-2010, 13:53
In almost all data I've found the heavier for caliber(230/45-180/40-147/9) bullets loose less fps per inch of barrel than the lighter offerings
The trend continues-the lighter the bullet the bigger the loss


and herin lies the problem with that.

its the heavy bullets that are velocity challenged to begin with.

Dandapani
01-31-2010, 14:01
and herin lies the problem with that.

its the heavy bullets that are velocity challenged to begin with.

Heavier bullets are slower, but have sufficient momentum for penetration and expansion... Unless your are talking about energy dump, magic fairy dust, then yes lighter bullets have more energy to "dump"... :rofl:

Steel Head
01-31-2010, 15:06
Heavier bullets are slower, but have sufficient momentum for penetration and expansion... Unless your are talking about energy dump, magic fairy dust, then yes lighter bullets have more energy to "dump"... :rofl:

:agree:


When some Pee'd off BUFF is comin to squash you flat what do you persuade him to desist with ------a 22-250 or a 470Capsticky :whistling:

That said-with today's ammo in it's normal grain range-if you have a 9mm,40 S&W 357SIG 45 acp or gap or 10mm in a short barrel gun
Your better off practicing more and worrying less

Scott in Houston You NEED a 33

Scott in Houston
01-31-2010, 15:44
Scott in Houston You NEED a 33


haha. :supergrin: Yes. I think you're right. What better to go with the G27 & 26 than another gun that will fit the same holsters, etc. :)

I would bet I own a G33 to compliment my G32 by mid February. :wavey:

sigcalcatrant
01-31-2010, 15:53
When considering sub-compact barrrel lengths, do some rounds start to look better or worse than others. For example, since there is less barrel to burn up the powder, do the merits of a .357sig over a 9mm become lost as less time is allowed for the powder to burn.

When using a sub-compact platform do lighter faster bullets or slower heavier bullets gain any more of an edge.

Sorry if this is a repeat, but I couldn't find conclusive info on it.http://www.ballisticsbytheinch.com/45auto.html

Mrs_Esterhouse
01-31-2010, 19:40
Thanks! Interesting .357 stats. Now it looks like the 357 SIG is a very good performer with shorter barrel lengths.

No prob. The data was from Ballistics-by-the-inch just plotted into a XY graph.

LEAD
02-01-2010, 11:48
Thanks for all the feedback everyone.

DEADEYEGUY
02-02-2010, 00:24
There was an article I read about a year ago concerning the performance of 9mm, .40, and .45 out of short tubes. Most .45 rounds are tested out of 5" barrels. You lose alot going to 3" barrels. Plus it's low velocity cartridge anyways. Most 9mm's and .40's are tested from 4" barrels and are high pressure rounds. They don't loose that much by dropping to a 3" barrel. a rough calculation is you lose about 50 f.p.s. for every inch of barrel lost in a handgun. The thing that really determines how the bullet performs is not so much a matter of speed. It is a matter of what the "expansion envelope" is off the particular load.
The Gold Dot, Winchester Ranger, Federal HST, Corbon DPX, and some of the other modern hollow points have a very wide range of expansion. Stick with those and you should be fine. In fact a gunmag chrono'ed some9mm loads through a Walther PPS with a 3.2" barrel. The Cor Bon DPX and Powerball were moving along 1229f.p.s. and 1315 f.p.s.. That's still some impressive performance.

fredj338
02-02-2010, 00:31
In self defense ammo I don't see any big difference at self defense distances. At up to 25 yards I see nothing to be overly concerned about, except maybe in small cal handguns but maybe there is and I just don't get it. The difference in speeds and self defense distances offer me little concern in most ammos. Now shooting at one hundred yards , yeah, then I might take some consideration into bullet weight and speed, but not at self defense distances.
Am I wrong here?

Well, yes. JHP are designed to expand within a certain vel window. SHorten that window by as little as 75fps & the bullet may not expand. So the loss of vel does matter, just how much depends on the quality of the JHP involved. Here is a pic of a LHP to show how vel, even 50fps, can play havoc on bullet performance. http://img.photobucket.com/albums/v703/fredj338/45-215gr.jpg

glocksterr
02-02-2010, 06:15
Heavier bullets are slower, but have sufficient momentum for penetration and expansion... Unless your are talking about energy dump, magic fairy dust, then yes lighter bullets have more energy to "dump"... :rofl:


you got it backward mate. the heavier bullets are closer to the edge of expansion to start with and you are moving them even closer with a short barrel.


that is one of the main reasons behind my choice of a lighter round, more cushion in the expansion window.


YMMV!


EDIT: more fairy dust too if you believe in that sort of thing. :)

GunFighter45ACP
02-02-2010, 12:18
At SD distances, I'm less interested w/which round has the greater velocity loss, or how close their velo #s are to each other, I'm thinking more about the handling characteristics of each caliber out of the subcompact platform.

Snapper2
02-02-2010, 13:23
haha. :supergrin: Yes. I think you're right. What better to go with the G27 & 26 than another gun that will fit the same holsters, etc. :)

I would bet I own a G33 to compliment my G32 by mid February. :wavey:

or use your g32 barrel in your g27. I did. Works fine. I also had a g33 barrel for it. Same gun different barrels.(27/33)