One more vote for shotgun. An AR is no good for home defense for a number of reasons. Maneuverability in close quarters, ballistics, etc. Shotgun with a pistol grip and 18" barrel is great, but you've got to have an adjustable beam flashlight, bore-sighted to the gun, so the 00 Buckshot spread covers everything that the light touches. However, buckshot will still penetrate beyond the perpetrator and through walls easily.