http://ammo.ar15.com/project/Self_De..._FAQ/index.htm

For indoor use I wouldn't use a rifle unless I was 100% sure of
backstop. The way my place sets I can shoot about 2 directions without a
big problem, but the other two could cause neighbors to fire back !!!

I have always liked a shotgun for indoors with a pistol as a get to the
shotgun or easily portable weapon. For carry a VERY dependable handgun
in a caliber that you can reliably shoot. Like I tell folks, Big bores
are great for stopping power, BUT if you cannot shoot it well because of
whatever reason you may as well grab a bat.

--
Steve W.