I hear a lot of trainers, You-Tubers and internet uh, experts say that 9mm is the minimum viable caliber for self-defense, and .380 ACP is too weak. Huh. Real Life would be very surprised to hear that. Greg Ellifritz compiled the results of a great many real-world shootings and discovered that overall there wasn’t a nickels worth of difference in effectiveness between the calibers between .380 ACP and .44 Magnum.

Service calibers and magnums are demonstrably much more powerful than .380 ACP and capable of doing greater damage. How is it possible that .380 could be ‘just as effective?’ The simple answer, as usual, is that it’s not that simple. Self-defense shootings involve a mind-boggling number of variables and caliber is only one of them. Also .380 ACP is hugely more likely to be employed by a civilian than a law enforcement officer, and as a result there are wildly different dynamics in play.

Briefly: a police officer is more likely to be involved in a gunfight. A civilian is more likely to be engaged by someone that is seriously not looking for a gunfight. It appears that in the majority of incidents of civilian self-defense any gunfire will result in the baddies attempting to disengage and flee. .380 ACP will invoke this effect as well as anything, and with the standard for a ‘stop’ being that the bad guy ceases all offensive action you can see where the statistics are skewed. This is referred to as a ‘Soft Stop,’ and as stated very often caliber is irrelevant to producing this.

OK, that’s the Soft Stop. But what about the Hard Stop? This is when you are required to physically disable someone in order to get them to cease offensive action. It is possible that one or the other service calibers is more effective than one or more of the others, but gun fights are such chaotic events that is is difficult to establish this definitively. In fact no handgun caliber is 100% reliable in producing a hard stop. After many years of study the FBI determined that a bullet must have sufficient penetration to reach critical structures in a variety of circumstances, it has to actually hit those critical structures and it’s good if the bullet expands and does greater permanent damage. OK, there’s the baseline.

Practically every caliber can meet the first two standards, from .22 LR on up. .380 ACP ball meets those standards, but since it doesn’t expand it is sub-optimal. This doesn’t mean it can’t work, but it reduces your margin for error.

There are however several expanding loads that do meet the standard for penetration and do expand reliably. Not all of them by a long shot, but there are several, and I’ll let you do your own research on that. So if we accept the FBI duty standard as the minimum then .380 ACP works with some loads. In civilian self-defense shootings even getting close to the FBI standard is probably sufficient. Probably.

So is the .380 ACP the minimum standard for civilian self-defense? As a rule of thumb I’d say yes. OK, why is it the minimum? Because Ellifritz’s survey showed a marked decrease in effectiveness for calibers smaller than .380. There could be a variety of reasons for this; the types of guns the smaller calibers are chambered in, the idea that more skilled shooters will choose the more potent calibers and the list goes on and on.

Mind you this does not mean that smaller calibers aren’t or cannot be effective, but on the whole why mess about with them if you have a viable option? At very least smaller calibers give less margin for error, meaning they can require greater skill to employ effectively in a broad variety of situations. Modern bullet designs may yet up the bar for smaller calibers, but the jury is still out on that.

Are there advantages to the .380 ACP over more potent calibers? Gosh, wouldn’t it be nice if there were a simple answer? For persons with low recoil tolerance due to injury, arthritis or other conditions the lower recoil and generally easier operation of the slide can be a definite advantage. Likewise the lower recoil of many platforms in .380 ACP make it easier to rapid-fire accurately for many people, and they may feel that trade-off is worth the potential hit in terminal ballistics.

Then there’s size. There are guns chambering .380 ACP that are significantly smaller than their 9mm counterparts, and below a certain size threshold 9mm gets notably more difficult to manage. It’s not unmanageable by a skilled and robust shooter, but there’s a point at which you might question if the longer recovery time between shots and pain during practice is worth the extra oomf.

We’re back to that whole ‘we’re all individuals,’ thing again. It may work better for some people for the reasons cited. For myself I can see trading the lower recoil and higher hit probability in rapid fire in a smaller gun as being worth it. I certainly wouldn’t feel helpless packing my wife’s P-238 legion, but if circumstances permit I will opt for a larger, more potent weapon. As always YMMV.

Michael Tinker Pearce, 3 April 2023