I use 1 1/4oz Nickel Plated BB's in my 2 3/4" 12ga combo guns and 1 oz of the same in my 2 1/2" 16ga drillings.
16ga drilling 44 yards
12ga combo 52 yards.
16ga drilling 39 yards
All shotgunned, with having the rifle barrel handy I don't have to reach far with the shotgun barrels and the loads are easy on the old guns and shooter.
If I'm restricted to just the shotgun I use a Rem 870 Turkey gun with 3" Rem HD BB's, 3" Dead Coyote(stock up when I find them cheap), 3" NP "F" or NP BB hand loads. I rarely ever have to rely on the shotgun only.