I really only shoot cast in my 450 Nitro Express, 450/400 Nitro Express. 45/70 and even my 375 H&H...using A5744 and a closed cell foam filler.

I water drop the bullets and they end up pretty hard...but even so, I stay away from large, slow powder that rattles around in the case.

Staying with this very general formula I've gotten pretty good results, not much if any barrel leading and more than acceptable accuracy.