Is the Gap Between 9mm and .45 Small?

[WheelGunRealGun]

I'm hearing a lot of people say that with modern expanding and +p ammo, the gap between 9mm and .45 is negligible when comparing a high-quality 9mm JHP +p to a high quality .45 JHP+p, giving the edge to the 9mm.

Is this true?

[Theohazard]

It depends what kind of difference you're referring to. If you're taking about the difference between the two calibers' abilities to stop a fight, there's no statistically significant difference between the two. This means that whatever difference there might be, it's just too small to be measured in studies of shootings involving those two calibers.

So when picking one of those calibers over the other, it doesn't make much sense to use terminal effectiveness as your deciding factor, considering the difference is so tiny. What makes much more sense is choosing based on factors that make a much bigger difference, like which guns you shoot best and can practice with the most.

[MarkCO]

There is no "edge", just minor differences. Common auto-pistol calibers, and the majority of revolver cartridges, are a compromise between a knife and a long gun. Handguns are around because they are more convenient. A huge amount of the calibers wars have "arguments" based on people's opinions formed from reading what others people's (and gunwriter's) opinions who are not well informed, have not been in an ER, have not examined GSWs in animals or people and who have not crunched the numbers. There are just too many factors to rely on a "golden BB" from any handgun. Proper training and techniques with a .380 WILL (over multiple events) be more effective than a newbie with a 10mm or .44 Mag. I can't recall the exact year, but the LE numbers were right at 21% of rounds fired by LE hit their targets and 19% of those hit by LE gunfire died. So if, in that year, LE shot at a person, they had a 3.99% chance of being killed. The caliber had little effect in that year. Even increasing the "odds" of a fabled OSS by 10% results in a very small change in the overall numbers.

Heck, do you know that there are two NEW bullets on the market claiming all kinds of superlatives, but not a single live target has ever been shot with them?

So, yes, the gap is relatively small. The gun you "feel" the best about and shoot the best will, for you, probably perform (over all possible situations) the best for you. I have a friend who has a .22RF as a defense firearm, I tell him it is "a little better than a knife" and another with a .460 S&W and I tell him it is "almost as good as an AR". But I can see situations where neither of those will be any good. Taking your handgun to the center of what the platform is capable of in terms of accuracy, energy, carry comfort, and capacity is all a personal balance based on a lot of factors which YOU are best to carefully consider and decide upon. I would not direct you to one caliber over the other, but the entirety of the package/platform for your constraints and environment.

[TXAZ]

A well placed 9mm round is much better than a not-so-well placed .45.
The number of analogs involved are so large that simple comparisons and generalizations are seldom precise.

[Darker Loaf]

This is not the be-all, end-all to ballistics tests, but I love that tnoutdoors9 actually puts bullets of various popular calibers through fairly non-biased and fairly scientific tests:

.45 ACP: https://www.youtube.com/playlist?lis...112947DB1DE491

vs.

9mm: https://www.youtube.com/playlist?lis...7CAFF8A6C0D3BF

From watching hours of ballistic gel tests from tnoutdoors9 and others, my personal opinion is that 9mm is equal to .45 ACP in many ways and in 147 grain varieties, it is often "better." "Better" in this case means generally meeting the FBI minimum penetration tests. .45 ACP often barely meets FBI minimum penetration tests. And while .45 ACP often (it does not always) make bigger holes than 9mm, it is not by much when hollow points of like brands are compared. Since .45 ACP is not a "death ray" as some have said, 9mm, in my opinion, is better because it is basically as deadly, but is cheaper and you can hold more rounds in a similar sized gun.

Oh my goodnesss! I must be bored. I accidently participated in The Dreaded Caliber Wars! Hope this doesn't get ugly...

[KyJim]

my personal opinion is that 9mm is equal to .45 ACP in many ways and in 147 grain varieties, it is often "better." "Better" in this case means generally meeting the FBI minimum penetration tests. .45 ACP often barely meets FBI minimum penetration tests.

That's true if you "cherry pick" certain rounds in 9mm and compare them with run of the mill .45 acp rounds. It also depends upon the exact tests (barrier vs. non-barrier).

[Darker Loaf]

That's what I was doing by cherry picking 147 grainers. Especially 9mm bullet weights below 115 grains seem like they underperform. My main point is that .45 ACP and 9mm are not very different, and that terminal performance is so close that it is secondary to other features (in my opinion): capacity and price.

[Colt46]

and they aren't, the .45 is superior to the 9mm. It makes a bigger hole.

Can everybody shoot the .45 accurately? Does having more bullets available make the 9MM a better choice?
It's all going to come down to personal preference.
Tailor your ammo to match your needs and you ought to do all right.

[nc-oldfart]

Don't forget theres a very practical cartridge between the two with the 40sw. Pistol are sized the same as 9mm not a wider heavier size of the 45 with most companies offer .

[jnichols2]

When I bought my .40 S&W two years ago, all the "experts" said not to trust your life to a 9mm. Today, my main carry gun is a 9mm.

I'm not ready for a .380 though. Most of them are too small for my hand. Also, it's very hard to find .380 ammo, and it costs more than 9mm when you can find it.

The .40 still has an advantage, ammo is always plentiful. The 9mm ammo is still hard to find at times.

[KyJim]

That's what I was doing by cherry picking 147 grainers.

But you didn't cherry pick .45s. Here's a test showing Federal .45 acp standard pressure 230 gr. bullets penetrating 13.75 inches of ballistic gel through four layers of denim and expanding to .892 inches. That's an .89 caliber bullet! And I have seen some results even better than that.

Don't get me wrong, I think 9mms are fine and sometimes carry one. But they are not equal to .45s. And don't start quoting "real world statistics" and one stop shot nonsense. Those are bogus. http://www.firearmstactical.com/mars...l-analysis.htm

[Oysterboy]

All that gel test proves nothing. When it comes to the SHTF you'd want ammo that can break bone. A 9mm might do it but a 40sw and 45acp WILL.

A bigger and heavier bullet it is the better.

[wncchester]

Considering the 9mm is a .38 Special +P with light for caliber bullets, there's little effective difference on paper targets.

[MarkCO]

And here we go again.

Something for the OP to ponder. Would you rather have a .45 that expends all of its energy and does not exit, or a 9mm that expends 80% of its energy and does exit?

Is a .45 ACP JHP more likely to plug up on thick materials and leather, or a 9mm JHP?

The .22RF will break bone in humans. I've seen the MRIs and X-rays doing virtual autopsy. I have also seen a .45 enter and exit with merely a flesh wound on a shoulder due to a collapsed JHP cavity that really was a COM shot. Energy analysis said a 9mm would not have failed to penetrate the same bone structure.

Handgun rounds, in general, incapacitate due to blood out and air in unless the T box or CNS is struck. So, in most cases, an entry and an exit and the largest permanent cavity is the goal. There are conditions that can be encountered where the 9mm might outperform the .45 and vice-versa, but in actual shootings, there is little if any difference in the actual incapacitation time and wound severity.

Bullets through living tissue loses a predictable amount of energy at tissue interfaces and on a per inch basis. That is why when testing over gel, we put 4 layers of denim, BUT, we do not simulate skin, fat, muscle, tendons and connective tissue in the gelatin. Using Fackler boxes, that can be done more easily, but the models still are approximations. Live tests are still the best, but there are so many hurdles, that it becomes difficult. With some states having wild hogs and other relaxing the regulations w.r.t. handgun caliber hunting, we have been able to get more data in the last several years, and some of it has surprised some folks.

I'll admit that I am not playing exactly fair as my work affords me the opportunity to analyze and evaluate these issues in depth. I will also admit that my views have been altered based on direct observation, analysis and testing that few people have the opportunity to see and participate in.

[zombietactics]

Handgun rounds, in general, incapacitate due to blood out and air in unless the T box or CNS is struck. So, in most cases, an entry and an exit and the largest permanent cavity is the goal. There are conditions that can be encountered where the 9mm might outperform the .45 and vice-versa, but in actual shootings, there is little if any difference in the actual incapacitation time and wound severity.

Word.

[Theohazard]

Originally Posted by MarkCO

There are conditions that can be encountered where the 9mm might outperform the .45 and vice-versa, but in actual shootings, there is little if any difference in the actual incapacitation time and wound severity.

Exactly. This is starting to become a caliber war, with people comparing minor technical differences between the two calibers. Honestly, if people spent more time practicing and less time trying to find the "perfect" caliber and defensive load, they'd be a lot better off.

[iMagUdspEllr]

Bullets are used to stop someone by causing a large enough volume of blood to be lost or by rendering the CNS incapable of functioning properly.

The difference between a 9mm and a .45 is .095" in diameter. So if you miss a vital organ by .095" then a .45 might have still grazed that vital organ. But, a 9mm usually gives you a few extra shots to compensate.

That and the lower recoil offered by 9mm seems to give 9mm the edge in my eyes. .45 ACP has the advantage if you don't want as much deflection when shooting through a windshield or other barriers (but then 9mm still gives you a few more rounds to compensate).

If the difference in recoil was reduced (using a heavier gun) and the difference in capacity was minimal then the .45 ACP has a clear edge if shooting through barriers is a concern.

[skizzums]

i prefer 9mm because it affords me faster follow-up shots and more shots in a smaller package

i like small and fast, on my own un-professional testing(phonebooks, gel, etc) i find my 9s to expand more reliably

professionals, LE and military use both, i wouldnt concern yourself with the rhetoric, shoot what you like

but i will say that if i lived somewhere that restricted me to ball ammo, i would go with 45

[dsa1115]

A 9MM or 40 S&W may or may not expand, but a .45acp will never shrink.

[farmboy]

Did I read correctly somewhere that Col. Jeff Cooper even proclaimed that the .22 Magnum could be proven to be a superior defensive round?

Can anyone fill me in on this one?

[OldMarksman]

Regarding wounding effectiveness, most of us can only base our opinions on what we have read.

Magazine capacity is something factual that we can look up.

The effects of felt recoil on shooting effectiveness is something we can determine by shooting.

Noise, in terms of decibels, is something we can research, also.

I tend to believe from what I have read that the first of the above is not really a discriminator. To the extent that that may be true, that leaves the other three.

[DATL]

Everyone mentions penetration on these ballistic gel tests, but when you watch the gel get hit by 9mm bullets it hardly shakes compared to the .45 bullet which in some of the videos flips around. The kinetic energy causes damage too right? I can't imagine that shockwaves wouldn't when you're talking organs? That small mm difference between the two seems to make a large difference there. I alternate carrying 9mm, .40, & .45.

[Officer's Match]

I too see all the scientific/medical reports claiming permanent cavity is all that matters, but I cannot completely discount kinetic energy so readily.

[Don P]

Did I read correctly somewhere that Col. Jeff Cooper even proclaimed that the .22 Magnum could be proven to be a superior defensive round?

Can anyone fill me in on this one?

The search function will get you the answer you ask for. I cannot find the link that I posted as well as other links and statements about the 22 mag. The article I posted describes it as a wicked round.

[OldMarksman]

Posted by DATL: The kinetic energy causes damage too right?

Not according to this.

I can't imagine that shockwaves wouldn't when you're talking organs? That small mm difference between the two seems to make a large difference there.

Not that it is exactly the same thing, but the impulse that creates those "shock waves" doesn't damage your shooting hand very much, does it?

Actually, I grew up holding much the same belief, and I was quite surprised to find that in the defensive handgun category, kinetic energy is not really very important at all.

That was after I had bought a .45.