I'm sure this has been mentioned, but you can get a trigger lock for a handgun. If you have to fire a shotgun at an intruder, evern rock salt, you're going to mess up a lot of stuff in your house. I'd recommend a semi-automatic handgun (the sound of the slide action makes for a nice warning to intruders). I have a Walther PPK. It's light, compact, and is a .380 grain, which packs a lot of punch. Also, if you have a handgun for self-defense, make sure to use hollow point ammo. If you fire it inside, hollow points will stick into the first object hit, rather than going through a wall or piece of furniture and hitting something on the other side.