From left to right: .357 Magnum, 45 ACP, 9x19mm, .45 Colt, .38 S&W, .25 ACP Bottom Right: .38 Special
This keeps coming up. over and over. OK, seriously- which bullet has the most Stopping Power? There is an actual answer, but you aren’t going to like it, because it is not .45 ACP. It is not 9mm. It is not even .357 Magnum.
The bullet with the most stopping power is the one that breaks something your attacker cannot function without. This means the bullet penetrates deeply enough to hit that thing, and- here’s the part that you won’t like- you have to make sure it goes there. Sorry, there is no magic bullet that will do it for you. No, if you hit them in the big toe with your 45 it will not kill them instantly. .44 magnum is unlikely to actually tear someone’s arm off- and if it does that may not stop them.
Some guy in the Korean war shot a couple guys with a .45, and it worked. His assumption was that this meant it was the only thing that worked. This became like a religion in some parts of the gun culture. 9mm? ‘Bah! If you shoot me with that and I ever find out I’ll kick your ass!’ .38 Special got an even worse rap. And anything smaller? Puh-lease! You might as well spit at them!
The sum total of our knowledge about handgun ‘stopping power’ came from anecdotes and some really, really unscientific tests performed early in the 20th C. Tales of one-shot stops with .45s were like candy, and never mind there were also plenty of stories where it didn’t. There were also stories where someone dropped like a stone after a single shot from a .25 Auto. ‘Just a fluke,’ we were assured. The fact is for any caliber- up to and including .44 Magnum- one can find tales of them failing to stop someone. Equally one can find a story just about any caliber dropping someone with a single shot. But people tended to only focus on the one’s that supported their pet theory or preference.
Now we don’t have to rely on anecdotal evidence. People have studied actual shootings over a period of decades to see what really worked in real life. What they discovered is that any service caliber- that being .38 Special, 9mm, .357 Magnum or Sig, .40 S&W, 10mm, .44 Special, .45 ACP- all work about the same. If you use a modern hollow-point they all work a bit better- but still about the same as each other.
Coroners report that among these calibers- presupposing the use of a good hollow-point- the only way they can identify the caliber that caused a given wound is by finding the bullet. Seems unlikely- these rounds have wildly varying amounts of energy and expand to different sizes in ballistic gel. The fact is that human tissue is not ballistic gel- it is inconsistent in structure and density and very elastic. Yes, a more powerful bullet may produce more damage- but not as much more as you might think, and the evidence suggests it’s not enough to make a difference in something that happens as fast as a lethal confrontation. Adding power adds penetration more than it adds damage, and that’s great if you are hunting large game. Less vital in a lethal encounter.
Calibers smaller than .38 Special get a little more complicated. Sub-calibers like .22LR and .25 ACP may not penetrate deeply enough to cause a solid ‘stop,’ and may not do enough damage if they do. Best bet with these is quantity- but not quantity over quality. You still need to hit things that matter. If you can put a half-dozen of these in someone’s heart-or face- in short order they are likely to reconsider their life-choices.
Small calibers like .32 ACP , .32 S&W Long, .380 ACP and even the venerable .38 S&W can all do the job, but hit location is crucial with these calibers- even more so than with service calibers. Generally hollow-points are not a worthwhile proposition for these cartridges; either they don’t expand and the round behaves like ball ammo, or they do expand but don’t penetrate deeply enough to interrupt vital structures. Best to use ball ammunition in the semi-autos and wadcutters in the revolver cartridges. Options to this in .32 ACP and .380 ACP are offered by Lehigh Defense in their Extreme Penetrator and Extreme Cavitator bullet designs; these seem likely to be somewhat more effective than ball ammunition. There are also a couple of hollow-point offerings in .380 that may perform adequately, but I am a bit leery of them.
In a self -defense situation a bullet can produce one of two kinds of stop. The first and most desirable is a ‘Hard Stop.’ This means they stop because they have no choice; you have broken a part of them that they cannot function without. This can be produced by a hit to the central-nervous system or upper spine. This is the only thing that will reliably produce a Hard Stop, but multiple hits to the heart are almost as effective. This is good thing, because in the heat of the moment it’s a lot easier to hit the middle of someone’s body than it is to hit their head.
The second and far more common is the ‘Psychological Stop’ or ‘Soft Stop.’ This occurs when you shoot them and they decide, consciously or unconsciously, that they are done. People don’t like to be shot. It’s traumatic as hell and it can be fatal, and your brain and body want nothing to do with it. Pretty often the fight/flight/freeze instinct kicks in and they run away or simply fall down. Sometimes their brain decides, ‘Nope. Shit got real, we’re done now.’ Sometimes they consciously realize they’ve been shot and decide their best chance to survive is to not get shot anymore. Whatever, when a ‘Soft Stop’ occurs the person stops being a threat, either by running away or effectively surrendering.
Any hit from any bullet can produce a ‘Soft Stop,’ but it’s more likely to happen if the person notices they have been hit. It is possible that this is where service calibers have their largest advantage- they produce more damage, which means there is a greater likelihood that a person will notice they have been hit. People involved in a gunfight have to be told they’ve been shot surprisingly often; they did not experience a Soft Stop because they weren’t aware that they’d been hit. This seems to happen less frequently with service caliber and larger hollow-points. This can be viewed as an argument in favor of calibers like .357 Magnum, .45 ACP and 10mm, but this is often argued to be countered by 9mm’s ability to put more accurate rounds on target faster.
Soft Stops are common and probably that’s what will happen if, God forbid, you are required to shoot someone in self-defense. But it might not- in which case your only option is a Hard Stop, and that probably means more bullets. One Marine was asked, hit for hit- which caliber he preferred. He shrugged and said, “Who shoots them once?”
It does seem clear that while small calibers may work your best bet is a service-caliber using modern hollow-points. Whatever caliber you choose to defend yourself with, you need to make sure you can hit what you aim at- preferably quickly and more than once.