Yes, there are still macho, mouth-breathing dinosaurs that insist that anything less than a .45 is a waste of time. But frankly the evidence is not on their side; in real-life shootings all service calibers (.38 Special, 9x19mm, .357 Sig, .40 S&W &.45 ACP) perform similarly when modern hollow-point ammunition is used- at least in service-sized weapons. Most people consider these the minimum calibers that should be considered for concealed carry. The snub-nosed .38 Special remains a favorite, and recently there have been a spate of sub-compact 9x19mm pistols but it is possible to get a reasonably concealable gun in any of these calibers. So are the smaller calibers- .22LR and magnum, .25ACP, .32 ACP and .380- still necessary and relevant?

All other things being equal it can be reasonably argued that they are not.  The smaller 9mm guns are pretty easy to carry and conceal, and many of them are no bigger than some of the .380 and .32 offerings. The problem is all other things are seldom equal. If you go to the beach even these diminutive guns might be a bit much, but a North American Arms Pug .22 Magnum can ride in a swim-suit pocket pretty unnoticeably. Likewise a Baby Browning .25. But are these tiny calibers ‘enough?’

From the perspective that ‘any gun is better than none’ they arguably have a place in your system of carry, inadequate as they are. But just how inadequate are they really? To answer that question we have to delve into the nature of armed self-defense.

Generally speaking civilian defensive shootings are fundamentally different from ‘on-duty’ shootings. Generally only 2-3 shots are fired. Generally these shots are fired at a full-frontal target at point-blank range. Police and military engage a much wider variety of targets, and these are not necessarily full frontal. Police shootings often involve an exchange of gunfire, and on occasion turn into protracted battles. They need the capability to penetrate light barriers, and to have their bullets reach vital structures even if a limb or light cover is in the way. A service-caliber, high-capacity gun suits their needs best. For most civilians self-defense needs people can, and usually do, get by with a lot less gun.

Most civilian uses of firearms for self-defense probably don’t involve firing at all. Merely competently displaying a firearm seems to be sufficient in many cases. It’s difficult to quantify this, because such incidents seem to be badly under-reported, but there is strong anecdotal evidence that this is the case, and for this nearly any weapon that is readily recognizable as a gun is likely to be effective.

But let’s suppose that you do need to fire- what is the goal? Simply put it is to stop your attacker from doing whatever it is that made you feel it was necessary to shoot them. This doesn’t mean dropping them dead in their tracks. People don’t like being shot. In most cases when someone is shot their instinct is to run away, take cover or surrender. Because if they don’t you might shoot them again, and if getting shot once is bad…

From this perspective it really doesn’t matter what you shoot them with. But suppose you are that one-in-a-million case where the perpetrator’s desire to get you overrides their instinct to flee. Will the small-calibers do the job? Yes- and no.

Handguns on the whole, even service caliber guns, are unreliable at stopping a truly determined attacker. It has been determined that the only way to reliably stop someone with any handgun is to hit something important- the central nervous system, the heart or major arteries being the most effective. Multiple hits work better than single ones. To hit these structures you need to penetrate deeply enough into the body to reach them. You need to shoot accurately enough to hit them, and the bigger the hole you put in those structures the better off you are. But the most important thing is to hit them; a good solid hit with a .22 is more likely to do the job than a bad hit with a .45.

The standard set by the FBI for penetration is 12-18 inches in calibrated ballistic gel after penetrating four layers of denim. This does not represent similar penetration in a human body- for one thing human bodies contain bone and organs of varying density. It has simply been found that bullets that will do this generally penetrate deeply enough in a human body regardless of the angle the body is at relative to the gun or if a limb gets in the way. But as previously mentioned most civilian self-defense shootings are full-frontal, requiring less penetration to achieve the desired effect.

All of the small calibers offer ammunition that will achieve 9-10 inches of penetration in these tests, even when launched from the smallest commercially available handguns. This ought to be sufficient for the vast majority of civilian shootings. Would it be better to use a service caliber gun? Of course- but if that is not an option you don’t need to feel pathetically under-armed with a smaller-caliber gun. These weapons can and have worked in the past, and they will continue to do so. But they will also continue to fail…

The single most common reason for failing to stop an attacker with a handgun of any caliber is simply not putting a bullet through something important enough to force them to stop. No matter what gun or caliber you employ you need to be able to shoot it quickly and accurately, which brings us to the real failing of truly small guns- they are hard to shoot well. They don’t fit well in most people’s hands and usually have minimal sights that are difficult to acquire quickly. They are also the guns that people are least likely to practice with. “It’s just a back-up…” In reality it is even more important to be proficient with these guns since you are already somewhat handicapped by their relative lack of power and penetration.

One piece of advice I see frequently is that if you are going to use a small caliber you should use full-metal case ammunition. This is under the assumption that you need to duplicate the penetration of a service-caliber weapon, which is unlikely to be the case. The problem with this is that small caliber full-metal case round-nose ammunition, most notably .25 ACP and .32 ACP, have an annoying tendency to deflect off bones. Skulls and even ribs have foiled these rounds on numerous occasions. The edges of hollow-points can dig into bone, which can allow them to penetrate instead of being deflected. If you do your research you can find hollow-points in these calibers that offer surprisingly good penetration- even in .25 ACP.

A case can be made for .22LR in a very small gun, if for no other reason than that it is quite a bit less expensive to shoot so it is cheaper and easier to practice with. The downside is that rimfire ammunition is a bit less reliable than centerfire, and the rimmed cartridge was never designed to function in autoloaders; it can be less reliable than other choices. This isn’t a consideration in a revolver, of course, and there are a number of small revolvers in this chambering that hold as many as nine rounds- of course these are as large as .38 Special revolvers that hold five rounds, at which point you might well be better off with fewer rounds of a larger, more effective caliber.

.25 ACP is often laughed off, but again modern ammunition makes a difference. There is at least one hollow point out there that expands reliably and penetrates an average of 10 inches in standard testing from a two-inch barrel. The downside is it’s expensive and increasingly difficult to find. .32 ACP is a better choice; cheaper, more readily available and more options for bullet designs and manufacturers. It also makes a bigger hole, which doesn’t hurt. .380 is the largest of the small calibers, and if you don’t need absolutely the tiniest possible gun it’s the best choice. There are even a couple of loads that actually meet FBI test standards. There are some very small guns chambered in this round, but if you are at all recoil sensitive you might be better off considering a .32; the recoil of some small .380s can be quite snappy.

Do your research and find a hollow point that works, or play it safe with FMJ loads if you want- but I would not recommend frangible ammunition like Glaser safety Slugs in these small calibers. Real-life shooting data for service-caliber Glasers seems to indicate that in most circumstances they will be as effective as modern hollow-point ammunition for civilian uses. But the smaller, less powerful sub calibers seem likely to be markedly less effective than conventional bullets, and there is just not enough real-world data available to refute that impression. Until there is I would avoid them.

Speaking of avoiding things I would avoid derringers as well. They only offer two shots, are awkward to use and generally as large and heavy as compact semi-autos that hold more rounds and are easier to fire. The do offer the option of two shots of a potent caliber, but their size and relatively poor handling characteristics offset this in my mind. The other problem with them is that basically they come in two flavors- cheap and unreliable or expensive. For a reliable, well-made modern derringer prices start at about $500. Really? For a two-shot, overweight dinosaur? If you insist on a pocket single-action a North American Arms micro-revolver is a better choice. They’re still kind of awkward, but at least they are tiny and you get five shots.

The keys here may seem familiar… fire your gun enough to be certain you can put rounds where you want them quickly. Do your research to find an effective load and make sure it functions in your gun. Aim for vital structures in the central nervous system or circulatory system. In a lethal encounter any commonly available, reliable gun can be enough. Whether or not it is depends more on you than it does the gun or caliber.

Addenda– Just after writing this I did a little more research on .32 ACP.

How about a load that exits a 2.7 inch barrel at over 1000fps, creates the kind of permanent wound track you expect from a good hollowpoint and achieves 13.5″ of penetration in standard FBI testing? Sounds incredible, but the Lehigh Extreme Cavitator .32 does all of this. Not just according to the company that makes them, but in independent tests as well. This is a standard-pressure load, too, so you don’t need to fear shooting it in older guns. Color me impressed!

That bullet profile ought to feed pretty well too. Not saying this is the ultimate .32 ACP, but it’s easily the best that I’ve seen. Price is competitive with other high-quality defensive ammo, too.