Straight WW balls (hardened if you want), just under calibre - say a .725" in a 12 bore with the cup of a trap-wad underneath to keep it centered - another cup-down on the powder with whatever wad is needed inbetween to get proper crimp height - roll or folded criimp - I used folded crimp with plastic cases. Work on the loads - I got excellent accuracy to 100 yards - 8" -10". 3" at 50 yards going 1,500fps for a 575gr. ball. They'll outpenetrate most of the slugs available, including Brenneke's, yet disrupt as much or more material in-path, shattering bones instead of bouncing off them. Some guys even get doubles to regulate - but you've got to move the balls. Can easily be more easily loaded with black powder. The normal 12 bore loads ran 110gr., 150gr. and 191gr. (4, 5.5 and 7 drams- Greener)

Of course, this is for someone who wants to load. Can be done easily with a hand set of Lee Loader Tools and a hammer or more equipment - but not much is needed. Word of caution- alwasy use 1 or 2 hard card wads between black powder and any plastic wads. Straight plastics, with integral base wads are easily cleaned of BP fouling - any paper very much less so.