Talk me out of/back into .45 ACP

[phylodog]

Interesting. I haven't seen that formula used before. I wish there were a reliable method of correlating these measurements to actual performance on targets but that would require an enormous amount of data collection and there are simply too many variables involved.

I suck at math. What would a 9mm round which expanded to .77" and penetrated 13.5" come out to via this method?

 

[88E30M50]

Interesting. I haven't seen that formula used before. I wish there were a reliable method of correlating these measurements to actual performance on targets but that would require an enormous amount of data collection and there are simply too many variables involved.

I suck at math. What would a 9mm round which expanded to .77" and penetrated 13.5" come out to via this method?

That looks like it would come out to 3.82 cubic inches per round, 11.4 cubic inches per 3 rounds and 61 cubic inches for a Glock 19 (15+1). That's really good in expansion, but loses a bit in penetration.

 

[phylodog]

That looks like it would come out to 3.82 cubic inches per round, 11.4 cubic inches per 3 rounds and 61 cubic inches for a Glock 19 (15+1). That's really good in expansion, but loses a bit in penetration.

Yessir. Had one go 18.5" but that was through heavy clothing.

 

[One Shot One Kill]

One good thing did come out of this. It put the Sar K2 45 on my radar and I just had to have one. Thanks to the OP I got a heads up on a smoking deal and was able to pick one up for $369 with free shipping and was able to pick up two mags at $24 each from CDNN. I plan to get out and shoot it today and if it shoots as well as the reviews say it's going to be a great day.

As far as 45acp power goes compared to everything else, I don't care and look at it like this, if it didn't work somewhere along the line it wouldn't be over 100 years old and in constant production the whole time.

Congratz on the new K2, glad I could help! Great gun, just wasn't one I really felt a need for.

 

[RW97]

Keep the 45, always nice to have one around, even though you may not shoot it every weekend or at all even, better to have it with a mag full of SD ammo or even FMJ's. A 45 cal bullet is still a 45 cal hole. Even if it didn't expand.

 

[prescut]

The most questionable statement in 7 pages:

And 8 rounds of 9mm +P beats 5 rounds of .38 +P any day of the week.

Too many variables to make that kind of assertion. I think he means redheads are sexier than blondes.

 

[Route 45]

The only variables are the launching platforms. Although you can hot load a .38 +P to equal a 9mm +P, most 9mm +P commercial loads beat .38 loads for velocity and muzzle energy for a similar weight bullet. And they are basically the same caliber, .355 vs .357. Eight always beats five in my book.

 

[dman424]

Just remember you are slinging half ounce of lead at the bad guy with a .45 ACP whether you get expansion from hollow points or just use ball ammo it's a big whole with a lot of energy behind it plus it won't over penetrate.

 

[Hohn]

Just remember you are slinging half ounce of lead at the bad guy with a .45 ACP whether you get expansion from hollow points or just use ball ammo it's a big whole with a lot of energy behind it plus it won't over penetrate.

You know, I wonder if a baseball at 100mph hurts a bunch more than a basketball at 50mph. I'm guessing it does.

 

[RustyHornet]

You know, I wonder if a baseball at 100mph hurts a bunch more than a basketball at 50mph. I'm guessing it does.

Depends on the size of the baseball....

 

[Route 45]

You know, I wonder if a baseball at 100mph hurts a bunch more than a basketball at 50mph. I'm guessing it does.

I'm wondering what pain and game balls have to do with anything.

A baseball is about 2.9" in diameter. A basketball is about 9.5" in diameter. Your comparison is not even close to 9mm vs. .45.
A 9mm does not move at twice the speed of a .45. In bullets with comparable sectional density for each caliber (147 grain 9mm vs. 230 grain .45), the velocities are generally within about 100 fps of each other.
Barring a CNS hit, volume of tissue destruction is the key. Not how much a baseball hurts.

 

[deadsquirrel]

460 Rowland conversion and be done with this discussion......

 

[churchmouse]

Have you sold the Sar K2?

You realize this thread is a year old right..??

 

[88E30M50]

Ah, but it was a good one though. If I recall, it provided internet proof that .45 will make bad guys evaporate with even so much as a near miss. Hey, has anyone ever compared a 9mm to a .40? Now that would be an interesting thread.

 

[BehindBlueI's]

Hey, has anyone ever compared a 9mm to a .40? Now that would be an interesting thread.

 

[gregr]

Knock down power is an ambiguous term, but you are right about a .45 having a greater level of capacity to damage than smaller calibers. If you calculate wound volume with expansion and penetration, it shows that a .45 will have a greater capacity to damage which gives a greater chance of a stopping shot. If you look at the numbers to see what the wound volume is for the first three (most critical and usually only) rounds fired, a good .45 round gives nearly double the capacity to damage over common 9mm SD rounds. Even the best 9mm SD round comes up 30% short of a .45 in capacity to damage in the first 3 rounds.

So, why do I choose a .45? Statistics show that the chances of getting into an extended gun fight are minimal for the average non-criminal citizen and that in an SD situation, the first three rounds are likely to be what decides the outcome of the gun fight. Given that, I am all about making those first three rounds count the most, so I carry .45 normally with an occasional jump to a .40. As luck has it, .45 is what I shoot best, so it's a win-win.

BAM!!!!!!

 

[gregr]

The tech in the new 9mm rounds makes them do almost as much damage as some 45 so I'd boil it down to what do you shoot best with and what's most functional for carry. However I definitely wouldn't go down to a 22

Tell yourself whatever you have to, to feel good about the 9 mm...

 

[gregr]

On a more serious note, I don't trust a .45 to penetrate. Having personally witnessed .45 slugs stopped COLD by a standard 3.5" hard drive, it really made me question the ability of the round when bone or cover is involved.

The best proxy I know of for penetration is something I call 'sectional momentum' which is just sectional density times velocity. Even a hot 230r load at 900 fps is pretty low on sectional momentum about 145 ft-grains per second. (if I'm not botching the units).

Compare that to a 147 gr 9mm at 1020fps, and only 132.6 f-g/sec for sectional momentum.

For reference, here are some other loads I figured up for comparison:

Caliber	Bullet wt (gr)	Sd	Velocity (FPS)	Sectional momentum
.357 SIG	147​	0.167​	1250​	208.75​
.357 SIG	125​	0.142​	1475​	209.45​
10mm Auto	200​	0.179​	1200​	214.8​
10mm Auto	180​	0.161​	1300​	209.3​
10mm Auto	155​	0.138​	1500​	207​
9mm	115​	0.130​	1300​	169​
.40sw	180​	0.161​	1000​	161​
.40sw	155​	0.138​	1300​	179.4​
.45 ACP	230​	0.162​	900​	145.8​
.45 ACP	185​	0.130​	1200​	156​
357mag	158​	0.177​	1475​	261.075​
44mag	300​	0.233​	1300​	302.9​
38spl	158​	0.177​	950​	168.15​
44spl	200​	0.155​	950​	147.25​
9mm	147​	0.130​	1020​	132.6​

Note how .357 Sig, 10mm, and more powerful calibers leave .45 in the dust for penetration. Also, these are some pretty hot loads in their respective calibers.

ETA: I'm pleasantly surprised that pasting in that table from Apple's "Numbers" apps worked so well!

https://www.americanrifleman.org/articles/2015/4/16/throwback-thursday-the-fbi-ammo-tests/

 

[gregr]

Yup, old, old thread, but...even though I carry a .380 generally due to much better concealability, Were I able to conceal better, I would only carry a .45 acp. On occasion, I will carry the Glock 30, and I feel much more comfortable with that pistol than the Glock 42. I love the guys who mock with the statements about how just the thought of a .45 makes bad guys die. Kinda the same silliness of those destined for Darwin Award fame who believe they "only have to rack the slide" of their shotgun to make the bad guys run. (They won`t know until it`s too late that the sound of them racking the slide of their pump-gun will only let the intruder know where to shoot.)


Nevertheless, what caliber one carries is nearly as personal a exactly which gun one carries. It`s fun to debate the merits of different guns and different calibers, but most have their minds made up, and nothing will change their minds. For me, it`s been the .45 acp for a long, long time.