Handgun stopping power arguments rage throughout the gun community, most often 9mm vs. .45, but we’ve all seen about every conceivable variation over the years. Evan Marshall tried to study this back in the 1980’s by studying real-life shootings.  His study was flawed by only examining the percentage of incidents where only a single shot was involved. Still, we began to see a trend even then- statistically there didn’t seem to be a nickel’s worth of difference between service calibers.

Then a few years ago the FBI announced that they were going back to the 9mm, because their thirty years of studying the topic indicated no significant difference in stopping power between service calibers, therefore they will go with the caliber that offers the most shots in the magazine, the lowest recoil impulse and the greatest ease of training for a wide variety of personnel. It probably didn’t hurt that it’s also the cheapest of the options- a fact which many in the gun community seized on as the real reason, to the extend of accusing the FBI of being so eager to save a buck that they were putting the lives of their agents in danger.

Recently Greg Ellifritz published the results of his study of 1700 real-world shootings. What he discovered was informative, because he looked at the data in a different, and I think more relevant way. First we need to get some terms straight- what do we mean by ‘stopping power?’ In this case it means the attacker immediately ceased all hostile action– not one more shot fired, not one more blow thrown. If they were running they must have fallen within five feet and not undertaken any further hostile action.

We’re not really worried about lethality here; in a defensive shooting the overriding concern is that the attacker instantly stop doing whatever it was that made it necessary to shoot them. So the first relevant statistic he uncovered was the percentage of times a given handgun caliber produced a stop with a single hit anywhere on the body. This worked out to be about 35% of shootings– regardless of caliber. Pretty much every caliber fell within a 5% range, which does not represent a statistically significant difference between calibers.

These are examples of a ‘Soft Stop’ or ‘Psychological Stop.’  It happens because people don’t like being shot. Their brain, either consciously or unconsciously, says, “Nope, we’re done.”

The next relevant statistic was how many times a single hit to the head or torso caused a ‘Stop.’ This could be a Soft or Hard stop- the data doesn’t differentiate. Single hits from handguns to the head or torso produced a stop, either ‘Soft’ or ‘Hard’ an average of 2/3 of the time. This was regardless of caliber or whether hollow-points or ball ammunition was used. Some calibers were at the low end of this range, some at the high end, but none of them fell outside the standard margin for error. In other words no single handgun caliber stood out as significantly more likely to produce a stop with a single hit to the torso or head than any other caliber.

This is pretty counter-intuitive; I mean, seriously, a .22 handgun is as effective as a .357 Magnum? It seems unlikely. That’s when we get to the next category- failure rates.

Ellifritz’s data indicates that most calibers fail to stop with one or more hits to the head or torso about 15% of the time- except for .22, .25ACP  and .32ACP. These three calibers result in three times as many failures to stop as the other handgun calibers studied.  That’s far outside the range of statistical error. Essentially what his data indicates is that .380, .38 Special, 9mm, .45ACP. .357 Magnum etc. all work about as well in real-life shootings. .22, .25 and .32 work significantly less often.

This data is hemmed about in caveats of course. .22 and .44 Magnum had relatively small sample sizes, semi-autos might be less likely to produce single-hit stops because their high rate of fire might mean that additional shots were fired after the subject was stopped by the first shot etc.  Nonetheless the basic data appears sound, and moreover is in agreement with my own, less scientifically rigorous observations spanning several decades, and even more or less in agreement with the FBI’s extensive studies.

So we should all be carrying .380s? No. Other factors enter into it- barrier penetration, heavy clothing’s effect on penetration, concealment requirements etc. If you expect to encounter dangerous large animals this might affect your choice; large, fast heavy bullets pretty conclusively do work better on large animals, and they won’t work less well on human attackers. Also these are pretty raw figures; their are other factors that are not taken into account. A hit with a .22 to the cerebral spine will almost certainly stop someone. A hit with a .44 Magnum to an extremity might not. Yes, just like in real estate it’s location, location, location.

The conventional wisdom since the 1970 has been to put multiple hits center-mass. It’s good advice- it’s the part of the body that moves least, it’s the biggest target and the heart, aorta, and spine are all there. Multiple hits in that area will be more likely to disrupt some or all of these structures, which is likely to stop the attacker sooner rather than later. This is true with any caliber bullet, but it is significantly more likely to work with calibers .380 or larger.

So what should you carry? Any gun, in any caliber, that you can rapidly and reliably put hits on target with that meets your needs for carry and concealment. If circumstances allow carry a weapon .380 caliber or larger– provided you can rapidly and reliably put hits on target. If high penetration is a requirement carry a 9mm, .357 Magnum, a 10mm or other gun known to have high penetration– provided you can rapidly and reliably put hits on target. If dangerous animals are in the equation something that fires a large, heavy bullet at a decent velocity– provided… well, you know. If you want to stack the odds the smart money says to carry modern defensive hollow-points, and there’s no way that more shots is a bad thing.

I have two guns that I carry regularly. If more discretion is required I carry a custom S&W .38 Safety Hammerless in .38 S&W. It holds five shots comparable in power to a .380. It’s loaded with lead semi-wadcutters. If enough clothes are being worn to conceal it properly I carry a Detonics Mk.1 Combat Master .45 that holds seven rounds. It’s loaded with modern hollow-points.

Two very different guns with very different ammunition– so what’s the common thread? I can rapid-fire both guns with a high degree of accuracy at defensive ranges, I enjoy shooting them, and they are easy to carry.  Objectively there are better choices; guns that are lighter and hold more rounds, but these two work for me. That’s what really matters in the end- that you are comfortable with the weapon, have it with you when you need it and can employ it effectively.

Michael Tinker Pearce, 1 September 2018