An AR is a great home defense weapon, and while, yes it will go through walls, as a good guy, you cant shoot through walls. You cant see your target. Bad guy doesnt have that constraint. But while the 556 or 223 round will go through a wall, it will likely lose both energy, stability, and direction by doing so. Even small bushes can deflect a 223 round enough to miss a target at relatively short ranges.
A shotgun is an area weapon, and while many say its the best home defense weapon, it comes with constraints. Lots of training involved in using a shotgun for a hostage like situation where friendlies are mixed in with your adversary. If an intruder grabs your kid, are you going to use a shotgun? I'd rather have the carbine.
Points of clarification:
- At home defense ranges with defensive ammo (e.g., 00 buck) a shotgun is not an ‘area weapon.’ Typical spread is very small; perhaps 2-3” at 10 yards (I suppose one could buy super-cruddy buckshot and a tiny, open cylinder gun and open it up, but for home defense, that’s just asking for a problem). Only on TV does the shotgun magically wound anything it’s pointed near.
- Noise wise, anecdotally the AR is louder; but anything from a .32 ACP up is loud enough to cause hearing damage.