A couple of thoughts FWIW:
Guns are much more purpose-built than a novice recognizes. While all will kill, there are trade-offs. Some kill more efficiently at a defined distance and some are better at keeping the shooter out of trouble.
For pure home defense, a shotgun is a good choice, but only with a few caveats:
1) It should be a 12ga. Lesser rounds will kill, but not as efficiently. A 12ga also has more stopping power.
2) A pump gun is usually the best choice. Autos are ok, but most hold only 3 rounds and a novice often fires behind a moving target. If you aren't a good and calm shooter, you don't want to run out of rounds.
3) Choose one that has at least a 5 round magazine. Many hunting shotguns only hold 3. Some of the older Ithaca Model 37 riot guns hold as many as 7 in the magazine and 1 in the chamber for a total capacity of 8.... this is the one I'd choose, but any I chose would be in an older configuration that allows "slam-fire" - the type that allows the gun to fire subsequent rounds (after the first) by holding the trigger and shucking the slide..... with the trigger held, every time a shell is loaded, the weapon fires.... a devasting amount of firepower when 8 rounds are available to a good shooter.
4) If it's not already done, cut the barrel to the shortest length allowed (usually 20"). A longer barrel in close quarters can be trouble. The longer barrel takes more time to get on target, can get hung up moving through doorways or on furniture - and worst of all, in very close proximity to an attacker, is fairly easy to side-step and then provides a handle for the attacker to grab and take the weapon from you.
As Curtis said, for rifles at medium range, you want semi-auto or slam-fire - and a lot of magazine capacity. Bad guys can cover a lot of ground in a hurry. Leave the bolt-action rifles for hunting only..... they're great for sniper use, but you should never have that requirement in a home environment. I can't imagine a scenario where I'd need a semi-auto rifle to defend my home, but I suppose anything's possible.
For pistols, semi-autos are good for putting out a lot of rounds in a hurry, but not if a shooter can't find the safety or forgets to flip it off. It takes a lot of practice for some semi-autos to become second nature, so give consideration to the safety simplicity and intuitiveness. A revolver doesn't hold as many rounds, but it's fairly idiot-proof in fast, reactive use - and if 6 rounds won't do the job, you're in trouble no matter what you're shooting. For the same above reason of stopping power, I like my .45ACP 1911, but I would not hesitate to use a .38 revolver. My 5-shot .38 S&W Chief's Special snub-nose is a favorite and although it's a bit small for my hands, it's easy to carry and quick to bring on target. Many deride a 9mm, but in semi-auto, they're very useful.
Whatever you choose, take a firearms course and get a lot of range practice. The time of need is not when a fellow should learn the basics of shooting.
Frank
