Buck F
NES Member
For home defense you probably shouldn't be thinking of getting a rifle...the projectiles penetrate too much and travel too fast to be able to fire safely in a small setting like a house. A 12 guage shotgun will stop anything in line of sight, but will also not penetrate walls (or at least not with still lethal velocities) endangering other members of your household in adjacent rooms.
.223/5.56mm penetrate less than most common handgun and shotgun rounds. I see a lot of commentary here about the various shotgun loads that should be used but almost no mention of the variety of AR rounds that are available. There are soft nose hollow point .223/5.56 rounds that will not penetrate walls anywhere near what birdshot or handgun rounds will and are as deadly if not deadlier than birdshot. No one is saying to use green tips in an AR for home defense, there are plenty of low penetrating defense rounds to choose from. You also have the ability to modify/accessorize an AR like virtually no other weapon, you can make it very light & maneuverable for very tight quarters while still being able to reach out and touch someone fairly easily at 100 yards. Throw a red dot or laser on it and you'll hit whatever you're pointing at in close quarters multiple times.