[awkx]

Overpenetration: Anything that can stop a man will go thru at least one layer of drywall at the same distance. But some bullets will even exit your house and enter your neighbors'. To avoid that, consider using frangible bullets. Even better, as jmateer succinctly pointed out, use a shotgun. Use large-size birdshot (e.g., BB size) or small-size buckshot (e.g., #4) if you're especially worried about overpenetration. But even 00 buckshot is probably better than your average pistol bullet.