Last week I wrote an article titled 'In defense of larger handgun calibers'. It attracted a fair amount of attention, and 18 comments (so far). It also drew a few e-mails from readers, arguing for and against the points I made. Based on that discussion, I think some aspects of the subject deserve further attention.
The first is that in some parts of the country, magazine capacities are limited by law. In New York state (the most restrictive so far), they're technically restricted to seven rounds, although I'm informed that provision isn't being enforced at present. Nevertheless, according to that state's SAFE Act of 2013, even larger-capacity magazines are supposed to be loaded with only seven rounds. Colorado and New Jersey have 15-round magazine limits. Several other states and the District of Columbia enforce a ten-round magazine limit, although some (not all) permit owners of pre-ban larger-capacity magazines to retain (but not necessarily use) them.
Even without possible legal restrictions, smaller handguns frequently have a limited magazine capacity due solely to their size. For example, the Springfield XDS pistol in .45 ACP (my current choice for a large-caliber pocket carry pistol) holds 5 rounds in a standard magazine (probably the only practical choice for pocket carry), or 6 or 7 in an extended capacity magazine (plus one round in the chamber, of course). The 9mm. version of that pistol holds 7 rounds in a standard magazine, and 8 or 9 in an extended one.
Other smaller handguns and so-called 'pocket pistols' (e.g. the Glock models 42 and 43, Ruger LCP and LC9s, Smith & Wesson M&P Shield, etc.), and standard 1911-style pistols, are also limited to ten rounds or less in their magazines. Small revolvers (so-called 'snubnosed' models) are usually limited to 5 or 6 rounds.
Given such capacity limitations, one wants to use the most powerful round that one can control. Each round has to work harder than it would if one had the luxury of being able to fire a lot of them without worrying about reloading. In last week's article, I quoted Jim Higginbotham, whose rule of thumb about how many rounds it will take to stop an attacker is "2-3 hits with a .45, 4-6 with a .40, 5-8 with a 9mm". Based on my own (much more limited) experience, I have no hesitation in agreeing with him as a general rule (although, of course, a single accurately placed - or lucky - shot from even a 'mousegun' cartridge might stop a fight at once; however, one can't depend on that in the heat of the moment). Given limited magazine capacity, I therefore want the biggest, most powerful cartridge I can control in rapid, aimed, accurate fire. Under such circumstances, I'll choose .45 ACP over smaller alternatives, and .40 S&W if I can't have a .45. In a pocket pistol, I'll select a bullet that performs best out of a short barrel, and preferably one that isn't dependent upon expansion to do its job. (For example, in a .38 Special snubnosed revolver that's not +P rated, I prefer Buffalo Bore's hard-cast wadcutter round.)
I was initially reluctant to carry a .45 ACP pocket pistol, because when I tested some models (such as these two) I found them very awkwardly shaped and hard-recoiling (to the point of being physically painful) and difficult to shoot accurately. However, when I tried the XDS, I found it much more ergonomic, comfortable and controllable. After putting over a hundred rounds downrange through it, I decided the heavier bullet weight and added momentum (discussed last week) of the larger round made it a worthwhile option. I still carry a small .380 ACP pocket pistol as a backup to a larger weapon, but I simply don't trust the smaller round to do an adequate job of personal defense. I also have a 9mm. version of the XDS, but out of a shorter barrel, any cartridge is limited in the energy it can generate, even in a +P or +P+ load. I therefore use it for training (9mm. ammo being a lot cheaper than .45), and carry the .45 for serious purposes.
(By the way: if you find a .45 pistol heavy in recoil and hard to control, there's a very simple 'cure' for the problem. Fire a few rounds of .44 Magnum - under trained supervision, of course. The much greater recoil, blast, flash and noise of the .44 will instantly make the .45 look tame by comparison! I've used that trick when teaching novices. Once they realize they can control a .44 Magnum round from a large revolver, and hit the target despite its seemingly overwhelming recoil, they become a lot more comfortable with the .45 ACP round.)
The second element I'd like to discuss is the use or non-use of hollow-point or expanding ammunition. These rounds are generally more effective at transferring bullet energy to the target and inflicting fight-stopping damage, and are less likely to over-penetrate the target and pose a threat to innocent bystanders. However, the state of New Jersey forbids private citizens from owning or using them for defensive purposes, and other jurisdictions are considering similar legislation. If one is restricted to full-metal-jacket or so-called 'ball' ammunition, one loses all the advantages of expanding bullets. Under those circumstances, the bigger (i.e. wider) and heavier the bullet one fires, the better chance it has of stopping an attacker. It's not just a matter of weight or velocity, but of bullet area or cross-section. A 9mm. round has a frontal area of approximately one-tenth of a square inch, while a .45 round has an area more than 50% greater. That means the larger round doesn't have to get as close to vital organs, blood vessels, nerves, etc. in order to affect them. Its greater area can compensate, to a certain extent, for a less accurate shot.
The final aspect is one I discussed last week, but would like to re-emphasize. It's the problem of defense against animals. If one habitually goes for walks along streets where dangerous dogs might be encountered, or in rural and semi-rural areas where other animals might pose a threat, it's advisable to carry a gun that can deal with their potential attacks. Last week I cited an incident where my friend Lawdog experienced less than optimal results with an otherwise-highly-rated 9mm. round. There are many accounts of attacks by dogs where smaller cartridges and calibers did not stop the attack quickly enough to avoid injury to the shooter and/or their own dog(s) and/or others in their company. That's another area where a heavier cartridge and/or larger caliber has real advantages. A .45 has often proven effective against big dogs, cougars, wolves, etc. A 9mm. or .357 Magnum round, even using a hollow-point bullet, has sometimes proven less effective against such threats.
So, there are three more factors for your consideration when selecting a defensive cartridge. As I said last week, I'm not knocking the defensive potential of cartridges like the 9mm. at all. I carry that round often, and trust my life to it. However, if magazine capacity is limited, and/or I can't use hollowpoint ammunition, and/or the threats with which I may have to deal are not necessarily on two legs, the bigger rounds do, I believe, have an advantage; so I'll use them for preference under those circumstances. IMHO, YMMV, and so on.