I've done some more playing with this load. Instead of paper patching I used some Teflon plumbers tape Three wraps gave me the dia. I wanted on a 158gr .357 keith type cast bullet. Using a Win large primer and 7 grains of H4759 with a very thin slice of foam to hold the powder against the primer, I'm next going to try florist foam. I can hold 4 shots in 1.5 inches at 20 yds offhand. I might also try modifying the case for a shotgun primer and no powder.
Bob