I know I'll get flack for posting this, but having fired literally tens of thousands of 12 gauge trap loads in my lifetime, and Melanie has fired thousands more that I've reloaded in all of our clay busting, I load my "House Gun" with 12 gauge trap loads. These consist of 1 1/8 ounce of #8's over 17.5 grains of Hogdon's Clays powder.
My reasoning is this. We, like many, live in a cookie cutter, track built house. It is a very nice home, but with that said I could easily kick my way through an outside wall with a pair of steel toed combat boots, and one of those "5 hour energy drinks". Bottom line, over penetration is a very serious issue! Shoot at a bad guy and accidentally hit a good guy, (neighbor), and you are looking at the a$$ end of a 6 or 7 digit law suit you will most likely lose depending on how badly you hurt, cripple, or outright kill them. To be honest shot size doesn't really matter across a living room or bedroom. The shot hasn't had enough distance to spread. If a 1 1/8 ounce trap load can break a clay target traveling at 60 MPH 35 yards away, it will easily cut a 2X4 in half from the sofa to the dining room table. I've tried it. Slugs are great, as are buckshot, but with these law schools spitting out lawyers like peanuts from a vending machine, you don't need anything from the muzzle of your gun going over your property line. If it happens when these ambulance chasers get done with you, you may be wishing the bad guy won! Just my .02 cents. Bill T.