There is no way in hell I would ever shoot my AR in the house. Thats what my 18" mossberg is for. I dont even want to shoot a pistol in the house bc Id go deaf. Well.. wouldnt want to shoot anything in the house but if I had to I would grab my shotgun. .223 has way too much velocity, penetration, and muzzle blast. I keep 12ga #4 buck loaded up. Sometimes I will have my 9mm on the nightstand but really that would be like a backup if for some reason I ran out of buckshot I would have 17 more rounds of 9mm. Pretty sure in the off chance I ever do need to shoot, 1 shot of buckshot will do the trick per invader.