We’ve come a long way in thinking about home defense. Function always comes first, but what most people think is important may actually be dangerous and detract from your ability to act effectively.
The prevailing wisdom for decades is this is the best option for home defense:
Shotguns provide a hard-hitting option with legendary reliability. There are many different shot loads and quick change parts that turn a turkey gun into a home defense gun, but they also come with some issues. First, shotguns are hard-hitting. A 12-gauge shotgun is essentially between a .50 and .73 caliber firearm and the kick from the recoil is pretty severe. It is exhilarating and you can get used to it or use lower power loads, but more recoil tends to mean less practice. This is especially apparent for women. Because shotguns have relatively heavy recoil they are relatively heavy to handle that recoil, both to keep the mechanisms intact and to absorb some of the recoil impulse. Heavy also translates to less used and less practice can be deadly. Shotguns usually have a barrel between 16 and 24 inches, but 18.5 inches seems to be the most popular length. That relatively long barrel means navigating tight halls and turns is more difficult and there is a risk of muzzle grab, that being if an attacker is close enough they can disable the firearm by grabbing and redirecting the muzzle. Shotguns traditionally were limited to 2–10 rounds, but newer designs and “half-shells” allow up to 41 shells (although that model, the KSG-25, has very long barrel). One of the most dangerous drawbacks to self-defense shotguns is “pump-freeze” or “short-stroking”. Most self-defense shotguns are pump-action because it is a simpler mechanism and thus less likely to jam or need maintenance often. The problem with this is we can’t be sure of our abilities in a stressful situation. One may find themselves frozen with fear and “forget” or be unable to rack the shotgun to fire or fire an additional shot, or one may only half rack the shotgun, which will not cycle the shell and load a new one, or there have been cases in which the defender racked the slide until the shotgun was empty and never fired. With self-defense, less is more, don’t add steps and processes if you don’t have to. In a self-defense scenario pulling the trigger is hard enough.
There are now bullpup shotgun options that mitigate some of the negatives, like length, grab factor, and handling (perceived weight and mobility), but the greater risks are still there, since most are still pump-action. There is also the added risk of overtravel by the support hand, which is a risk not only in a stressful situation but in normal practice as well. This happens when the supporting hand is placed in front of the muzzle and can result in serious injury. This happens for a number of reasons, including conditioning from training on other platforms (the muscle memory reaction that there is more grip there than there really is), vigorous pumping (we can all get carried away), or even defects in design, construction, or accessories (grip coming off unexpectedly, accessory grip coming off). The pump-action movement is inherently suceptible to overtravel by the support hand in some cases, like training for a self-defense scenario and thus working at the limit of speed. There are ways to decrease the chances of such an error, but the flaw is inherent in the motion of the pump-action. Because of this I would not suggest a pump-action shotgun with a barrel length that matches the pump length in a bullpup or traditional design.
Thanks to the AWB AR-15s have become the “gun of America”, so obviously many have suggested this as the best home-defense option,
AR-15’s suffer some of the same negatives of shotguns, namely length and weight, which is why AR-15 pistols have become popular lately. The general positives are increased magazine capacity, less complexity in operation, and a greater degree of customizability. You can set it up any way you want, just watch out for that mission creep,
The major negative of the AR-15 platform is the ammunition. The 5.56 cartridge is pretty good, and there are debates on penetration (some argue the light bullet is easily deflected and loses terminal velocity, others say the high velocity causes overpenetration), but it isn’t as effective as some other cartridges. That’s why recently the AR-15 and larger-bore AR-10 has been expanded to more calibers and variants, like .300 BLK, .223 Wylde, .224 Valkyrie, 6.8 SPC, 6.5 Creedmore, .458 SOCOM, .50 Beowulf, and more. In the case of 300 BLK all one needs is a different barrel and bolt, although most opt for a complete upper, and it can be used on a standard AR-15 lower with standard magazines (although there are 300 BLK optimized magazines now). Each caliber comes with its own pros and cons, and costs, so it takes some research and preparation. The 5.56 caliber is still the most popular for the AR-15 platform and with this caliber magazines range from 5 rounds to 150, but 30 rounds is the standard magazine capacity. The platform can’t get away from the standard weight and length, though, which is an important reason for the next suggestion.
For a decade or so now the popular refrain has been to go with a handgun for self-defense, but now we’re seeing the “geared” pistols come out,
Handguns have their advantages, namely in the realms of maneuverability, retention, and training. It’s easier to manage around corners and tight spaces, they can be used with one hand so you can manipulate objects or direct children, they are easier to retain in a grab situation, and can host a variety of accessories like a suppressor without being overly heavy or long. Most importantly, a handgun can be carried on one’s person and thus can be carried at all times (in compliance with Federal, State, and Local laws). The old axiom states, “Fear the man with only one gun”, the broader meaning that only having one gun comes with the presumption the owner has great experience with it, compared to someone with less experience with many guns. The skills trained for concealed or open carry (where and how legal) translate to home defense, and having that familiarity and confidence goes a long way. In more urbanized areas there are usually more pistol-only ranges, so there are more opportunities to practice.
The trend has been to add optics to pistols, namely red dots, to aid with better target acquisition, especially with aging eyes. A modern self-defense handgun can utilize a weapon light, laser, and optic, just like the AR-15, and most handguns have aftermarket parts or factory magazines to bring round counts up anywhere from 20 to 50 rounds, although with a 50 round magazine you could use it as a baton. With pistols, you get a variety of caliber choices, but 9mm is the most popular. Pistol calibers are deemed to be less likely to overpenetrate walls, but research shows if there are no hard materials in the way a 9mm round can go through four houses before stopping. Luckily houses typically have hard materials throughout.
The new hotness in home defense is the logical mix between the AR-15 and handguns, the Pistol Caliber Carbines.
PCCs are the civilian firearms that are most similar to submachineguns and have become popular recently due to a demand for self-defense oriented firearms whereas before submachinegun clones were an expensive niche. They combine the benefits of the AR-15, like capacity, accuracy, and uses pistol calibers to cut down on overpenetration and recoil. Combined with ATF-approved braces, PCCs can be very short and maneuverable. Using pistol calibers mean ballistics are not compromised by a short barrel, unlike 5.56 cartridges, and a suppressor can be added without making the entire package unwieldy.
There are a few new entries to the PCC market that have made the space more competitive, but better yet this trend has capitalized on the AR-15 craze, offering AR-15 based PCCs that can even use standard AR-15 lower receivers with magazine adapters. One must still be careful of ATF classification laws when swapping upper receivers or building a firearm, but it is straightforward.
From the trends, we can see there are a few things that are important to people. Maneuverability, capacity, weight, ability to mount accessories, size, and so on. You have to assign value to each of these categories based on your needs. Generally speaking, more ammunition per magazine is better for a number of reasons, but one major reason is you are not going to have time to gear up, what you have in the gun is what you have to run. Your accuracy in a stressful situation will not be good, you don’t know how many people have entered your home, and so on. One of the most important things is to practice with your platform until the actions are natural, more ammunition in the magazine means less time reloading and that enables more quality practice more rapidly. It doesn’t do you any good to have the perfect firearm and accessories for your situation when your stress response is to drop the mag and click the safety on (it has happened). Training isn’t a guarantee that will not happen, but the likelihood diminishes as the productive actions become more natural.
All these options are viable for home defense, but some are more suited than others. My opinion is 9mm is the most valuable caliber for self-defense, at home or away. Having a handgun and PCC that use the same ammo saves you money and simplifies the ecosystem. Your opinion may be different, but so is your situation. Get what you can comfortably run in the space you need to use it. The best shotgun in the world isn’t worth anything if you’re not going to practice with it and it has severe disadvantages in your space.