My side by side 12g with 3" nitro mags would decimate anything I aim towards. At 30' with bird shot #6 both barrels I leave a pretty large print and anything coming down my hallway or through my door is not going to know what hit them!
WOW! There's a home SD gun for you. Twice as much shot as you need, and if you miss in the hallway, you'll blow out Bubba's ear drums--and yours, too. Nobody will want to fight anymore---peace, Bro.
OK, once in a while I get a little humour streak, maybe the Red Bull. But, you don't need 3" mag's for home defense, and you can't make up for the lack of birdshots' penetration just by having more of it. Would be like the B1 bomber dropping 100 lb. bombs. I hear that Remington has a new HD load that uses #2 shot. I always called 'em goose loads, myself. At least that would be an improvement--and still lacking penetration thru a couch or a chair that Bubba might duck behind.