ACP vs GAP ballistics [Archive] - Glock Talk

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jmoln
01-11-2011, 21:31
Its been a quiet night so here is a discussion starter. I thought I wanted a .44 revolver for my next gun. I quickly decided I did not like shooting .44 magnum with a lightweight revolver (Taurus Tracker) and that a heavy S&W didn't fit the primary hiking application. Realizing I was going to use only .44 Specials I started to compare ballistics and came up with these numbers from the Speer website. Of course I have them all plotted in excel but can't figure out how to post that and why can't I get these numbers to line up? (I've attached a pdf of the plot)


Speer Gold Dot Ballistics fps ftlbs

44 mag 240 gr 1400 1044
44 sp 200 gr 875 340
45 ACP 5" 230 gr 890 404
45 ACP 5" 185 gr 1050 453
45 ACP 4" SB 230 gr 820 343
45 GAP 4" 200 gr 970 418
45 GAP 4" 185 gr 1090 488

When I saw the low energy numbers of the 44sp I started to compare the two .45 numbers that I know. Here are my presuppositions along with unexpected findings . . .
- ignoring the platform question, revolver vs auto or even which auto
- handloading is not an option at this time
- the potential application excludes grizzlies so .44mag is not required
- heavy grain .44 or .45 is preferred over smaller calibers
- all .45's exceeded the .44 special energy numbers
- barrel length is very important to ACP
- ACP does much better with 5" than 4"
- my 4.25" 1911 is equal to the .44 special (ok but not good)
- the energy numbers imply an efficiency advantage for the GAP
- the loadings wring more energy out of a 4" bbl in GAP than ACP
- I could go for a full size 1911 or since I used to own a G38 maybe its time to come back

Your thoughts?

dudel
01-12-2011, 03:20
Your G38 is calling you.

jmoln
01-12-2011, 06:25
Anyone out there have my old G38, serial number HCG900? I know its changed hands at least once since I sold it.

dbarry
01-12-2011, 16:39
somebody gonna post that pfunny icon with the guy eat'n popcorn??? :O)

KindaBigBullet
01-12-2011, 16:53
somebody gonna post that pfunny icon with the guy eat'n popcorn??? :O)

Soon. Here we go again.








:wave:













:popcorn:

dbarry
01-12-2011, 16:56
Soon. Here we go again.








:wave:













:popcorn:

nice!

KindaBigBullet
01-12-2011, 17:01
Your thoughts?


Who the hell made such a stupid chart?

Going back to grammer school days, the Y-axis is the speed. The higher up you go on the chart , the faster.

X-axis is just a list of different rounds. WTF does connecting the dots do? You need a "bar" graph for this.



Sorry, just vented a bit. Ooh, I feel better.

burgherdude
01-12-2011, 18:43
How funny! When I opened this thread I was actually eating a bag of Jolly Time popcorn! :supergrin:

jmoln
01-12-2011, 18:59
Ok, I'm back to defend my thesis. Attached is your basic bar chart. The independent axis is still the round, the dependent axis is velocity and energy. The main point of the chart is to compare how energy varies with respect to various bullet calibers and weights. One of my baseline assumptions (after bullet placement) is that energy is the primary consideration with caliber being a very close second.

Remember I started this discussion with a decision to try out a .44 revolver. After deciding I didn't want to endure .44m energy with a lightweight weapon I went back to look at other rounds. A long time ago I decided against the .40S&W as being too snappy. I've also left behind .380 as too small and 9mm as relying too much on velocity. The .38 survives only because of a small J-frame.

So, with the remaining rounds that have power equal or better than the .44 special I have either a 4" .357 or I move up to .45. This is where I learned something new. From this chart it appears that the ACP is biased/tuned toward the predominant 230gr 5" platform whereas the GAP does equal or better with a 4" barrel. Finally, back to my starting point - a lightweight platform with as much energy as I can handle. So I compare what I can get with a lightweight 4" or 5" 1911 versus the GAP with a lightweight Glock and I really see that I want to buy a Glock next.

Once again an emotional decision backed up by science and logic. :cool:

jwizzl497
01-12-2011, 19:11
Ok, I'm back to defend my thesis. Attached is your basic bar chart. The independent axis is still the round, the dependent axis is velocity and energy. The main point of the chart is to compare how energy varies with respect to various bullet calibers and weights. One of my baseline assumptions (after bullet placement) is that energy is the primary consideration with caliber being a very close second.

Remember I started this discussion with a decision to try out a .44 revolver. After deciding I didn't want to endure .44m energy with a lightweight weapon I went back to look at other rounds. A long time ago I decided against the .40S&W as being too snappy. I've also left behind .380 as too small and 9mm as relying too much on velocity. The .38 survives only because of a small J-frame.

So, with the remaining rounds that have power equal or better than the .44 special I have either a 4" .357 or I move up to .45. This is where I learned something new. From this chart it appears that the ACP is biased/tuned toward the predominant 230gr 5" platform whereas the GAP does equal or better with a 4" barrel. Finally, back to my starting point - a lightweight platform with as much energy as I can handle. So I compare what I can get with a lightweight 4" or 5" 1911 versus the GAP with a lightweight Glock and I really see that I want to buy a Glock next.

Once again an emotional decision backed up by science and logic. :cool:

Dude, this chart may be worst than the first. What data does Series 2 represent??

jmoln
01-12-2011, 21:05
you guys are worse than my college professors - always finding the weak spot. Just as with the first graph series 1 is muzzle velocity and series 2 is muzzle energy. See the attached chart.

jwizzl497
01-12-2011, 21:51
I'm sorry but an axis of a graph does not usually represent two different measurements. If it's muzzle velocity, then it isn't muzzle energy. It just so happens that it's somewhat understandable becuase the size of the numbers are close.

PS - I think the GAP and ACP are equal. I would only go with the gap if you prefer the smaller frame. That would be the only reason.

sgt207
01-13-2011, 05:05
Get another 38

KindaBigBullet
01-13-2011, 08:55
[QUOTE=jmoln;16654482]you guys are worse than my college professors - always finding the weak spot. QUOTE]

I'm sorry about my chart comment.

dudel
01-14-2011, 01:47
I'm sorry but an axis of a graph does not usually represent two different measurements. If it's muzzle velocity, then it isn't muzzle energy. It just so happens that it's somewhat understandable becuase the size of the numbers are close.

PS - I think the GAP and ACP are equal. I would only go with the gap if you prefer the smaller frame. That would be the only reason.

I guess you've never seen a speed vs horsepower vs torque chart.

Depends on how close they have to be to be "equal". Remington charts give GAP an edge. Small, but stll an edge.