The real difference, .45acp vs 9mm

[Mike38]

I just watched this video on You Tube "Maybe I Was Wrong About Pocket Pistols" https://www.youtube.com/watch?v=Cv6PxB2TqLM and I found it very interesting. Apologies if it's been discussed here before.

In the video, the guest 'Expert' made a statement that made my jaw drop. I re-watched that particular part three times, and hope I got it right. If true, it appears that the .45acp really isn't that great when compared to the 9mm. Matter of fact, hardly any difference at all.

When using the torso of an adult male as a target, and comparing the frontal area of a bullet, the .45acp is only 22/100 of 1% larger than the 9mm. (I think I have that right.)

I recently started carrying a Kel-Tec P32 .32acp as my only carry pistol. I questioned myself with this decision, but put it out of my mind because my main goal was to be able to carry something that was light weight. Very light weight. The P32 is without a doubt that, light weight. My previous carry gun was an all steel S&W J frame in .38spcl. That thing felt like carrying a brick.

So if the .45acp is only 22/100 of 1% larger than the 9mm, the .45acp is probably only one half of 1% larger than the .32acp. If I have all this correct, the .32acp is not really a dumb choice at all. Because of it's light weight, and ease to conceal, I carry more, and carrying more is a good thing.

Anyhow, interesting video, with other good points mentioned. Take the time to watch it.

 

[Aguila Blanca]

When using the torso of an adult male as a target, and comparing the frontal area of a bullet, the .45acp is only 22/100 of 1% larger than the 9mm. (I think I have that right.)

You have correctly reproduced what the guy said, but it's a stupid statement and totally meaningless.

What he's doing is comparing the area of the bullet to the total area of an average adult male torso. So that's a sliding scale -- compare it to the frontal area of a small person's torso and the percentage difference will be greater, and compare it to the frontal area of a large economy size male (maybe a pro football lineman) and the percentage difference will be even smaller.

However -- the area of a .45 caliber bullet is 60.6 percent larger than the area of a 9mm bullet, and that number doesn't change no matter how large or small the torso of an assailant is. (These are in-flight numbers. To compare expanded areas, you'll need to know the specific bullets involved and find expansion test results in ballistics gelatin.)

What we care about in a self defense round (what I care about, anyway) is the effective size of the wound. That's a combination of expansion and penetration. It has nothing to do with the area of the assailant's torso. A 9mm that expands may be more effective than a .45 that doesn't expand.

I watched the video. I feel dumber for having watched it. The guy obviously is a proponant of smaller calibers, and so his argument suffers from confirmation bias. As Mark Twain once said or wrote, "There are three kinds of lies: lies, damned lies, and statistics." What this guy has done is generate a meaningless statistic and expressed it in a way that appears to support his preconceived bias.

 

[Tygus.Shooting]

The points made in the video make perfect sense

Thank you for posting that link to the video, Mike38. I took the time to watch it more than once, and I believe that the points that were made about carrying pocket pistols are entirely valid.

The truth of the matter is that in any lethal encounter, the mere presence of a handgun is enough to resolve the situation 90% of the time. Almost everyone on the planet has been conditioned to believe that being shot is a bad thing and as a result, no one really wants to get shot with any kind of firearm.

The matter of caliber doesn't even begin to figure in the equation until the shooting starts, and if and when it gets to that point, it is usually the one who manages to obtain the first hit who prevails. The other party usually goes down or runs off, which constitutes a clear win when all we want to do in the first place is to get the offender off our case.

So you are actually right --- carrying a .32ACP (or any other gun, for that matter) is definitely NOT a dumb choice. It fulfils the first rule of gunfighting which is, to have a gun. I carry a .380ACP, a .22Magnum and even a .22LR at times, and do not consider myself at any great disadvantage when I do.

I have seen enough to know that no handgun can be considered a perfect man stopper. Handgun calibers are puny when compared to the stopping power that long guns can deliver. If all that my carry gun accomplishes is getting a perp to disengage, and allowing me to escape to safety, I'm perfectly happy with that outcome.

My position is: carry what you're comfortable with, but have it with you all the time!
____________________________

I love gun control. It lets me hit what I'm shooting at!

 

[Koda94]

The adult male torso is a bad metric to use comparing calibers but comparing calibers is a rabbit hole anyways.

The bigger issue here is I question if the Pareto Principle applies anymore today? Are defensive scenarios like mall or mass shootings and multiple attackers possibly with heavier firepower really the Sentinel Events anymore?

 

[kymasabe]

Watched it, I see his point but don't agree with the math. Torso size shouldn't be part of the equation.
That being said...I pocket carry a P32 too. I'd much prefer to carry a 9mm like a Nano or Hellcat, but doesn't conceal well on me and the P32 is small enough and light enough to go everywhere.

 

[Kreyzhorse]

Energy, mass and expansion are what I care about. Its how a bullet will likely act upon hitting a target.

Torso and bullet width aren't factors.

That said, carry what you can and any gun is better than no gun.

 

[peacefulgary]

I believe there is much more to ammo effectiveness than just the surface area of the slug.

For example:
The .357 magnum has a great reputation as a stopping round and it's basically a very fast moving 9mm/.38 Special.

 

[shafter]

I still subscribe to the idea that at the end of the day 45/40/9mm are all really small pieces of lead that move fast enough to punch holes in the human torso. Use good ammo and they will all likely get the job done if you put them in the right place. Put them in the wrong place and they are all equally as ineffective.

 

[COSteve]

When using the torso of an adult male as a target, and comparing the frontal area of a bullet, the .45acp is only 22/100 of 1% larger than the 9mm. (I think I have that right.)

While the guy may have said it, not only is the statement stupid, it's wrong.

If you take the diameter of the 9mm bullet (it's .356") and compare it to the diameter of a .45 cal bullet (it's .452") the .45 cal bullet 27% larger diameter than the 9mm. If one were to calculate the surface area of the 2 circles it's even a larger difference.

The 9mm at .356" diameter, has a surface area of 0.099538" while the .45 at .452" diameter, has a surface area of 0.16046". That means that the .45 has a 61% larger surface area than the 9mm, 61%! To say that they are the same is really stupid.

Add to that the mass difference between a 115grn 9mm and a 230grn .45 and it's hard for anyone to say that they are almost identical. In fact, it's impossible to say that with a straight face so his whole premise that one compares the bullets to the torso is bogus as the bullets impart their energy into the impact zone in completely different manners due to their vastly different sizes, weights, and velocities.

Yes, it's true that the Muzzle energy of the 2 calibers is much closer due to the 9mm significantly higher velocity and so performance of the 2 calibers may prove to be more close, but to say that the difference between them is trivial is just plain stupid.

 

[Mike38]

"Lies, damned lies, and statistics." It's what happens when you combine a mathematician and real world statistics. Proof that you can twist numbers to mean anything you want.

Interesting replies, thanks. I'll have to watch that video a couple more times to see if I can 'cipher this all out. Bottom line, carrying a Kel-Tec P32 is way way better than a sharp stick.

 

[Hal]

If I have all this correct, the .32acp is not really a dumb choice at all.

Of course it's not - after all, everybody knows it has a delivery like a brick through a plate glass window.....

 

[jmr40]

There is nothing new that hasn't been known and documented since at least the end of WW-2. The myth of the superiority of 45 over 9mm is largely due to the fictional writings of Jeff Cooper. Too many people chose to believe his drivel rather than look at facts.

By the end of WW-2 the military was disappointed in both the 1911 and the 45 ACP cartridge. In 1946 they did a lot of experimenting and concluded there was zero difference in effectiveness between the 2 rounds with equal shot placement. Multiple other tests and studies have always concluded the same thing.

But they also found that 9mm penetrated barriers far better, it recoiled much less, in the same size guns holds many more rounds, and most shooters were more accurate with a 9mm. Characteristics that did give the edge to 9mm. Especially for military use. The military wanted to ditch 45 in 1946. But budget cuts, no large scale war, and warehouses full of fully functional 1911's meant no money.

The .357 magnum has a great reputation as a stopping round and it's basically a very fast moving 9mm/.38 Special.

There is actually a lot of overlap. When you look at ballistics charts they show 357 mag from 8" test barrels. But from 4" and shorter real barrels expect 1200-1300 fps from 125 gr bullets. Almost exactly the same speeds as 124 gr 9mm ammo.

The diameter of the bullet is largely irrelevant. Relatively speaking both 9mm and 45 are SMALL holes. Penetration and placement are key.

 

[44 AMP]

When using the torso of an adult male as a target, and comparing the frontal area of a bullet, the .45acp is only 22/100 of 1% larger than the 9mm. (I think I have that right.)

I don't think that is quite right. As stated, the math doesn't work.

1% is 1/100th of the whole or 0.01

22/100 OF 1% would be 0.0022

.45 - .35 = .1

0.1 > 0.0022

IF you are comparing the difference in frontal area between 9mm and .45 to the area of a human torso then yes its not significant. But doing that has the same relevance to stopping an attack as comparing the 9/45 difference against the entire continental landmass of the United States.

In other words, it is MEANINGLESS.

Bullet size, weight, and speed all matter, but what matters most is where the bullet goes, and then, to a lesser degree, what it does when it gets there.

We call this "placement". And, it is the only factor entirely dependent on the person pulling the trigger. Directly after placement comes penetration. The bullet has to penetrate enough to reach and disrupt the vital area. Personally, I prefer a bullet with enough power to pass through the vital area.
I can't count on a bullet that stops short of the vitals to do the job I need done. I do count on one that goes all the way through the vitals.

A bullet doesn't have to expand in order to work. They need to go into/through the right place in order to work. ANY bullet that does that, works. Expanding bullets tend to work better, PROVIDED they penetrate enough while expanding.

A light gun, that you have with you when needed is vastly better than a heavier gun you left at home because it was like carrying a brick. l

 

[Aguila Blanca]

By the end of WW-2 the military was disappointed in both the 1911 and the 45 ACP cartridge. In 1946 they did a lot of experimenting and concluded there was zero difference in effectiveness between the 2 rounds with equal shot placement. Multiple other tests and studies have always concluded the same thing.

And after a few years in the Middle East our soldiers were (and still are, as far as I know) very unhappy about the performance of the 9mm M9 Beretta.

I remain of the opinion that the premise of the video -- purporting to use numbers to "prove" that the size difference between the .45 ACP and the 9mm is so tiny as to be insignificant -- is stupid. IMHO it's nothing short of intellectual dishonesty. That said, although my primary carry pistols are 1911s in .45 ACP, I do have a couple in 9mm and I have been known to carry pistols chambered in .380 ACP. I'm certainly not opposed to carrying a caliber smaller than .45, and I readily acknowledge that -- with new bullet designs -- the 9mm approaches the .45 ACP in effectiveness.

But not for the reason being promoted in that idiotic video.

 

[CDW4ME]

Chrono data from my pistols.

I do not own the 32 or 380 any more; I can and do carry a larger pistol.
Kel-Tec 32 Federal Hydra Shok 65 gr. @ 804 fps / 93# KE = .23 momentum
Kel-Tec 380 Federal Hydra Shok 90 gr. @ 845 fps / 143# KE = .34 momentum

Glock 19 - Federal HST 124 gr. +P @ 1,210 fps / 403# KE = .67 momentum
Glock 19 - Federal HST 147 gr +P @ 1,044 fps / 356# KE = .68 momentum
Glock 35 - (357 Sig) 125 HST @ 1,415 fps / 556# KE = .78 momentum
Glock 35 - (40 S&W) Federal HST 180 @ 1,019 fps / 415# KE = .81 momentum
Dan Wesson Valor - Federal 230 HST @ 891 fps / 406# KE = .91 momentum

KE and momentum are a way to measure "power".
A 357 Sig PPU FPJ @ about 1,460 fps has comparatively good level of "power" (for a pistol) but would be overpenetrative for SD against a human.
Not only do 32 and 380 lack "power" bullets in those calibers that can penetrate at lest 12'' and consistently expand (desirable criteria) are few.

All the 9mm/357Sig/40/45 HST's penetrate at least 12'' after heavy clothing and consistently expand.

9mm is the minimum I'd bet my life on, in reality I carry a Glock 23 or 35 most. I can dress as I choose, which is concealment oriented.
Nowhere would I prefer a pocket 32/380 in hand to defend myself rather than a Glock 23 and I carry accordingly.

As far a 9mm compared to 45 acp HST - think dimes vs quarters (pic)

 

[Wag]

44Amp and Aguila Blanca said most of what I believe.

Size used to matter a lot. Then the science of terminal ballistics and bullet construction/expansion techniques, etc. rendered size a little less relevant. Such science did, however, bring up some of the smaller bullets out of virtual uselessness into practicality, especially rounds like .380 ACP.

A person's intended use for a round matters a lot but what matters most, as mentioned above, is shot placement. There is no such thing as a comparison of stopping power because a .22 LR is lethal with a CNS shot, even on a very large animal. Or person.

Round count probably matters slightly less which is why I don't mind carrying a 9mm which gives me 16 rounds with no extra mags. Occasionally, I'll carry a .45 with 8 rounds but still, I feel that more rounds is better than bigger rounds, all else remaining the same.

--Wag--

 

[Forte S+W]

Personally, I've grown tired of the endless debates of calibers and their effectiveness...

Honestly, it's like watching an extremely boring court case in which the stakes have never been lower because neither side stands to lose anything, yet the prosecutor and attorney argue passionately, throwing statistics and anecdotes back and forth in a desperate attempt to prove their point, with the anticlimactic outcome being that neither is objectively better than the other, regardless of what either side asserts, and you really can't go wrong either way, thus rendering the entire debate, a pointless waste of time.

Personally, I carry .40 S&W, and I don't care how many folks tell me that I should totally carry something else, because it's what I like, and I'm not so easily convinced that there exists an ideal, one-size-fits-all cartridge for Self-Defense, regardless of what's trendy with Law Enforcement of the Military.

Besides, I have a hunch that despite all the folks who argue that the size difference is meaningless, that .45 ACP would gain a sudden boost in popularity in the event that the AWB were to return and folks nationwide were limited to 10 rounds or less.

 

[PolarFBear]

PLEASE -- no politics or "social" interaction: Seems we had a recent example of the 9mm not being truly a "one shot man stopper". Seven rounds and the "apprehendee" survives. I suggest seven rounds of .45 acp would have caused a quick bleedout and subsequent fatality.

 

[JERRYS.]

oh no, not another my dad can beat up your dad thread....

use the right ammo in the right gun for the right purpose.

 

[kell]

You are absolutely right. You get into things like permanent and temporary cavities, muzzle energy. The permanent "hole" will be almost the same for both. Velocity makes a big difference in the temporary cavity. More so than caliber. That's why .223 is so devastating. 3000fps vs 800fps (.45) vs 1200fps (9mm).