I like the idea of BB shot (I wouldn’t go smaller), but I don’t like they pretty much only come in 3” magnum loads.no buckshotn for me. I bad guy can ER and get sewed up from a .32 cal pellet. I use BB shot, there is no sewing up hamburger meat.
I have always advocated for #4 buck for home defense. Now if you live out in the country and don't have any close neighbors you might want a side saddle with heavier loads .
I take it you have no kids in the house.Mine are loaded with 00B. Mostly Federal Flite Control. Might load one of the tubes with 2 3/4" slugs in the big gun.
I take it you have no kids in the house.