9mm vs. .45 with a twist

[RX-79G]

Bob,
With respect, there was more than one is Vietnam experience, and I've read about tunnel clearing specialists whose experience differed from what you observed. You also like to talk about what you have read about the Moros - it was just different from what I've read. And really, I was just using that to illustrate a point that peak chamber pressure is a really poor predictor of muzzle blast and noise. And it is.

I don't believe in Power Factor because it is a made up concept used in a game, not a scientific principle based on either physics or (more importantly) wound analysis or statistics. Power Factor would not explain the bullet behavior of the original 1:14 rifled AR-15, either. Power Factor is a lot like Hit Points in Dungeons and Dragons - rules to make a game function.

In answer to your last question - wouldn't that be a better question for officers and soldiers using 5.7 pistols and subguns?

One last thought: I do have friends who were also in Vietnam. Why did one of them tell me how they illegally made dum-dums out of their .45 ammo? Because IPSC hadn't been invented yet? His unit felt pretty strongly about the performance of .45 FMJ.

[RBid]

Originally Posted by Hunter Customs

You also don't believe in power factor, if that's the case why not use a 5.6x15R shooting a 32 gr JHP at a little over 1600 fps?
It's easy to shoot with very little recoil for those fast follow up shots

Come on, Bob. There is a big difference between not subscribing to power factor, and stating that NOTHING is important except follow up shots. You know that. Your comment is akin to somebody suggesting that your emphasis on power over follow up shots means you may as well go to a single shot .500 S&W something or other.

[RX-79G]

The other reason Power Factor is meaningless is that it is not an actual measure of power or energy. Muzzle energy is a measure of kinetic energy, and those numbers would not have allowed Major and Minor, so IPSC concocted Power Factor because their unscientific multiplication of mass and velocity gave them the numbers they wanted and reflected a bias against low recoil calibers.


What's particularly funny about that is people on this thread saying that recoil doesn't affect combat accuracy; then referring to Power Factor, which is mainly a division based on recoil to prevent the low recoiling 9mm from out scoring .45 on a simultated combat course.


Some numbers:

9mm 124gr. Federal Vel. 1120, energy 345 ft/lbs, Power Factor 138.8.
.45 230gr. Federal Vel. 850, energy 369 ft/lbs, Power Factor 195.5.

Q. How can two bullets have 93% of the energy of each other and only 71% of the "power".
A. They can't. Power Factor does not measure anything in physics.


And I'm not suggesting that muzzle energy is the best predictor of performance. The point is that ballistic specs alone do not determine wounding potential. Cartridge design determines that, and FMJ is a very poorly designed cartridge for wounding potential.

In terms of this thread, the argument that .45 FMJ has X amount of additional wounding potential over 9mm FMJ has pretty much no basis, since neither cartridge is in common use by the kind of agencies that keep wound statistics, like LEAs.

Is .45 FMJ "better" than 9mm FMJ. For one round, yes. How much? No one has good data, but probably very little. And quite possibly so little that the additional recoil and decreased capacity are not a good trade off. But without a baseline for wounding with FMJ beside absurdities like "Power Factor" and 100 year old war tales, it isn't a question likely to get answered to anyone's satisfaction, or prejudice.

[fireboat]

I am a retired firefighter/paramedic from a busy south florida department and I have seen I guess several dozen shooting victims. With FMJ in many cases, there is a small entrance and exit wound which tells me that not much energy was transferred to the victim. So the more shots, the better and probably the bigger the better if you are comfortable with that.

I read the reports from the 1986 FBI shooting in Miami, one BG was shot 6 times before he died and the other was shot 12 times before he expired. They both continued to shoot and kill and injure the FBI agents after repeated shots from 38sp, 9mm and even 12ga buckshot. The one guy that was hit 12 times had a collapsed lung with 1.5 liters of blood in the pleural space. Ultimately it was fatal but not for a long while.

We all talk about shot placement but I don't think most of us realize how difficult that is in a shooting situation. The FBI shooting illustrates this with 8 FBI agents (well really 7) against the two BGs. Also, there was another shootout in Miami several years ago between a BG and a PD Officer that was caught on home surveillance. The BG and the PD Officer were about 10-feet apart when they were exchanging gunfire. The BG kept shooting after being shot 2-3 times. If the officer wasn't wearing a vest, I don't know if he would have survived. Still, here was a trained officer shooting at close range and it took what looked to be about 4-5 shots before the BG went down and died. I don't know exactly how many shots were fired or if the last shot was a kill shot or the guy bled out internally from the previous shots. The point is though, unless the first shot is to the CNS, the bad guy will most probably return fire even if you shoot him in the chest. But even trained LE often cannot deliver an immediately disabling shot with the first several shots. So I guess what I am saying IMHO is to use what you are comfortable with and practice with. I used to like a revolver, but now I have 9mm with 17+1 capacity knowing that it may take a lot shots to disable a BG.

[Avec Bien]

Yeah I think I read that the NYPD hits their intended target 1 in 6 shots(sorry no link right now). That is not hitting center of mass either that is just hitting anything at all. So it seems kind of lucky to hit a moving target under extreme stress.

[Rifletom]

Well, some like the 9mm, some prefer the .45acp. I like this:
"A 9mm might expand, but, a .45 will never shrink!" I like .45's. Nothing wrong with the 9's tho.

[RBid]

Originally Posted by Avec Bien

Yeah I think I read that the NYPD hits their intended target 1 in 6 shots(sorry no link right now). That is not hitting center of mass either that is just hitting anything at all. So it seems kind of lucky to hit a moving target under extreme stress.

IIRC, Portland PD at one time had the highest hit rate among U.S. PDs at something just shy of 50%. I can't recall the source for that. At any rate, it's a basic statement about the value of follow up shots, capacity, and training (not in that order).

Having recently run defensive scenario sims in a VirTra 300, 300 degree range, I can say that accuracy against movers, while moving, dramatically increases in difficulty as range increases. Even the difference between 3 and 7 yards is dramatic when both sides are moving. Human movement often involves a lot of speed fluctuation, directional change, and level (height) change. Factoring in the stress of trying to live, things can be incredibly difficult.

There are a lot of people running around who have never shot faster than 1/second, have never shot at movers, have never shot under stress, have never shot while moving, and have never been in a defensive gun use event, who toss around statements like, "if you can't get it done in 7 rounds, you shouldn't be carrying!" There are so many problems with that statement, it's crazy.

[peacefulgary]

It seems a single shot by a .45 fmj has more stopping power than a 9mm fmj. Does two shots by the 9mm fmj equal one shot by .45 fmj? Or is two shots by 9mm better? Or is two 9mm shots less good than one .45 shot?

With all other things being equal like shot placement.

With all other things being equal, two 9mm rounds on target is definitely better than one .45 round on target.

Think about it...

If you were going to be shot, would you rather be shot with one .45 round, or two 9mm rounds?

I would definitely choose one .45 slug if I had to be shot.


PG

[militant]

I think this thread is pointless. No intelligent person uses fmj for self defense and our military is using 9mm as far as I know.

[Nanuk]

"Stopping power" has to be the most misused and misquoted cliche in history.

Just because one study say bullet xyz has a 96% one shot stop rate does not mean that it stops "NOW"!

In the old west they had the "dead mans 5 seconds" and "dead man walking". There are hundreds of anecdotes of people being shot and stumbling around for a few minutes before dieing.

There are far too many variables to worry about. Pick a premium HP that your gun feeds 100% and take a break. FMJ VS FMJ? please.

[peacefulgary]

No intelligent person uses fmj for self defense

Not necessarily...

For example: Here is a link to a video that seems to show that when it comes to the 380 Auto, hollow-point ammo fails to provide adequate penetration vs FMJ 380 ammo....

http://www.youtube.com/watch?v=soNdX36P-3E

In the video linked above, the 90g 380 Auto Speer Gold Dot hollow-point round penetrated only approx. 9.5" in the 10% gel.
But the 90g 380 Auto PMC Bronze FMJ round penetrated approx. 19.5" in the 10% gel.

[dayman]

No intelligent person uses fmj for self defense

My understanding is that some states/municipalities don't allow JHP's. I'm thinking NJ, but if I'm wrong I apologize.
And it does make for a better, or at least more standardized, comparison. JHP comparisons are probably going to be effected more by the individual bullet than the caliber. While FMJ is pretty much the same no matter who makes it, there's a big difference between say, Federal HST's and Hornady CD's. Or even within the same brand, WWB JHP's to, say, Ranger T's. Or, even if you go with exactly the same thing, a particular bullet design can be more effective in one caliber than another.
There are so many variables with JHP's that the data can be used to show pretty much whatever you want.

But pretty much any way you play it out, I think 2 rounds of 9mm is going to be more effective than 1 round of 45. However, I'm not sure that that's a fair question.

I assume we can all agree that, for everyone, the 9mm is quicker for follow ups than the .45.
No matter how good you are 9's have less recoil, and thus take less time to bring back to bare. If you're not faster with a 9mm you're either inept, or - more likely - faking it to prove a point.
However, I don't think it's twice as fast. Or at least not for people that practice regularly.
A more accurate question would probably be "are 3 rounds of 9mm more effective than 2 rounds of .45?" or for people who train a lot (like most of those arguing here) "are 4-5 rounds of 9mm more effective than 3-4 rounds of .45?".
And, when you consider that most of us train to shoot 2 (or maybe 3) times regardless of what we're shooting, the question really becomes "is 2 shots of 9mm in 1s more effective than 2 shots of .45 in 1.5s?". Don't focus on the actual numbers, I was going for a qualitative comparison rather than quantitative.

I don't know as it changes the answer, and I - as a rule - do prefer 9mm.

However, it strikes me as illogical that we 9mm fans regularly point out that the increased performance from the .45 is marginal, but don't seem to want to admit that the increase in follow up speed with the 9mm is equally marginal.

That's if we're making an apples to apples comparison. My understanding is that the 1911 - probably the most popular .45 - is mechanically slower to return to battery than a lot of modern designs.
So, for say Beretta 92 vs 1911 it might be a considerable difference. But, I'd think comparing say a G21 to a G17 (or Sig 226 vs 220, etc.) you'd find that - in trained hands - the difference in speed, while still present, wouldn't be nearly as significant.

In a SD scenario - and I'm admittedly not an expert in this - it seems like the limiting factor you're going to have on your time is more likely to be the time it takes you to react and draw rather than the fraction of a second a well trained shooter is going to loose between shots.
If there are multiple attackers, or you're very close to your target, time would be much more of an issue, and - like I said - I do generally prefer 9mm, in part because it is a bit faster (though IMHO the increased capacity, and price of practice ammo are bigger draws to 9mm).

So, to summarize; when it comes down to it, the .45 just isn't all that much more "powerful", or all that much "slower" than the 9.
I wouldn't want to get shot by either. Though, I wouldn't really even want to get shot with a rubber band, so that doesn't say a lot.

And that's the end of my Novella on the subject.


PS: If someone wants to give me a G34 and a G41 (assuming we're right about what it is) for my birthday this spring, I would be more than happy to run all sorts of objective tests to settle the question once and for all. More than happy.

[Mike Irwin]

" They both continued to shoot and kill and injure the FBI agents after repeated shots from 38sp, 9mm and even 12ga buckshot."

Fireboat...

You need to refresh yourself on the particulars of the Miami shootout.

Matix was hit early in the firefight (about a minute after initial contact) and was knocked unconscious by a .38 caliber bullet to the head. At that point he had already been wounded in the forearm by another bullet.

IIRC he had gotten off maybe 2 shots and apparently wounded no one before he was permanently removed from the fight. He never exited the car (Platt did).

ALL fatalities and, I believe, all wounds to the FBI agents, were caused by Platt and his .223 rifle.

[pilpens]

Back to the original post -
Assuming that the 2 9mm hits are within 2 inches of each other, I think 2 9mm hits would produce more damage than 1 .45 hit.
I think 1 9mm hit on each leg would be more painful than 1 .45 hit on one leg.