There are four easily identified categories of defensive firearms. Each has its own strengths and weaknesses, and each has a particular role to play. Just like wrenches, you have to own the full set before you can do all jobs These four categories can be named, fighting handgun, back up / discreet carry handgun, defensive shotgun, and defensive rifle or carbine.
This is a full sized, easy to shoot, powerful handgun. It will be of at least 9mm-power level, and will allow you to easily make authoritative hits to well beyond 25 yards. You should be able to finish the qualification run in Pistol Skills 3 with this handgun under 15 seconds. This handgun should be the focal point of your handgun training. It will be with you most of the time, so it will probably be the one called upon to protect you. I recommend it be simply the largest, heaviest handgun you can tolerate wearing constantly. I’d like to think it will be at least the size of a Glock 19 / 23 / 32, or the Kimber Compact I normally wear. If you prefer revolver, it should be a three or four-inch barreled K frame Smith and Wesson or equivalent.
Back up / Discreet Carry Handgun
Simply put, this is the handgun you have with you on the days you just can’t wear a full-size fighting handgun. Or, it’s the second handgun you wear to back up your primary fighting handgun. It will be small, by necessity. Not so small that you can’t make authoritative hits with it to 15 yards or so, but small enough to be comfortable in a pants pocket or other discrete carry mode. My personal handgun for this role is a Smith and Wesson 442. It’s small, light, slick and smooth and not uncomfortable in a pocket holster in the front pocket of my Wranglers.
Universally accepted as the fiercest of the defense guns. Horribly powerful, incredibly intimidating, the short shotgun demands respect everywhere it goes. Absolutely my first choice for fixed place confined space defense. The shotguns only weakness is one of reach. With buckshot, my preferred load, you can’t rely on it past 25 yards. The shotgun doesn’t really increase the reach of my primary handgun, it just brings huge horsepower to the game.
Defensive Rifle / Carbine:
The rifle is the most versatile of all possible defensive hardware. More powerful than any handgun, and it offers more reach than most shooters can use. With a little training, close targets and confrontations are imminently manageable. In periods of anarchy, think LA riots or Hurricane Katrina, the rifle is most important piece of emergency equipment you own. A good generator and a supply of food and fresh water won’t help you a bit when the angry mob kills you, rapes your wife and daughters, and then takes your other emergency equipment. In such dire situations, I can think of nothing other than a semi automatic rifle I would rely on. Such a rifle offers me the reach to deal with threats at such distances that the untrained, pistol waving idiot is really no threat to me anyway. The power and capacity of such a rifle would offer me the resource to reason with a mob of 25 or so on my front lawn. When things are at their worst, the rifle will always be the best choice.