Ann, number 4 Buckshot but Buds is currently out. 2nd is low recoil 00 Buck Shot : budsgunshop.com/product_info.php/products_id/711007357/nobelsport+law+enforcement+buckshot+12+ga+2+1%2f4+in+1250+fps

alternating the Mini slugs and mini Buckshot budsgunshop.com/product_info.php/products_id/2446/aguila+1c128974+12+ga+manual+safety+slug+20%2f25 and
budsgunshop.com/product_info.php/products_id/713073270/aguila+ammo+mini-shell+12ga

BBB or 4B (B = buckshot), staggered with 000B. Example 6 shot tube; BBB (more pellets - smaller pellets)), 000B (less pellets - bigger pellets), 4B (bigger than BBB, but still quite a bit smaller than 000B), 000B, 4B, 000B. 000B needs a back stop, as it will over penetrate, but it is also needed to shoot through moderate barriers, like dry wall. BBB, and 4B will go through drywall too, if muzzle is close enough, say < 10'.