walmart has the winchester 1 oz box of 15 for $10 or so. remington also.
i have three 12ga mossberg 500 shotguns i cut to 20 inch barrel. all my ammo is 2 3/4". all my shotguns have the 5 shot carrier thing on the stock held in place with strips of bicycle tube like a big rubber band. on the other side of the stock i have 4 additional shells held long ways by the tire tube ban and out of the way of my face. and the 5 shells in the mag. thats 5 shells in the gun and 9 on the gun. each. plus a bandolier with 25 00 buckshot and 25 slugs.
shotgun one for in the house is loaded with 00 buck(remington or regular federal, or winchester).
second shotgun is loaded down with winchester pdx1(buck n ball) for really tough threats/outdoors that buckshot may not work on. according to tnoutdoors on youtube the regular 2 3/4" winchester slugs break up and penetrates around 10 inches of ballistics gel. the pdx1 buck n ball penetrates 19 1/2 inches! be careful!
third mossberg is to bring in the truck. i rotate federal flite control 00 buck and the winchester 1 oz slugs.
i'll post the buck n ball video in case someone has not seen it. you can checkout his other devastating 12 ga videos from there.