The Shotgun is one of the most powerful weapons in the self-defense arsenal. At the average range of a SD encounter, the power of this weapon is a force to be reckoned with. Its limitations are its size, which can limit its manuverability and ease of use by people of smaller size. Its recoil can be a limiting factor, as can its limited ammo capacity and speed of reloading. However with the proper ammo selection and training anybody can operate the shotgun effectively.
There are two types of ammunition for defensive shotguns: buckshot and slugs. Birdshot…not even worth mentioning.
Contrary to popular belief, shotguns do not spread shot into such wide areas that they do not require aiming. If they did, that would make it negligent to use them in self defense situations. You are responsible for where your shots impact. Generally, buckshot leaving a shorter barreled shotgun will stay together for a little past one yard, after which it tends to spread approximately one inch per yard. This means that most shotguns wont be able to keep all the pellets of a standard 00 buck load on a stationary target, faced squarely, past 15 yards. It is wiser to assume that you probably can’t keep all the pellets on your intended target past seven yards, especially under stress. It should also be obvious by this point that the shotgun requires aiming.
Magnum loads, which pack more pellets at higher velocity, tend to have greater spread. Which isnt really a good thing in a SD situation. “Tactical” loads, which have lower velocity than standard loads, often use hardened, plated shot and sometimes one pellet less, tend to have less spread. They also generate less recoil.
Shotgun use in home defense is principally a short range, from cover affair. As such, I would stick to buckshot due to its reduced likelihood to overpenetrate. Slugs, in general, are for precision and distance work. Since most homeowners wont be attempting to preform a hostage rescue with a shotgun, the first isnt much of an issue. If you are manning your homes defensive perimeter from alien attack then a rifle would be your better choice anyway.
Because the 12 ga. is the traditional bore for police shotguns, it offers more options: more guns to choose from, more variety in ammunition, and more accessories.
Stick to pumps or autoloaders. Single shots, doubles and over/unders just plain run out too fast….