Daryl, Thanks for the response. I have the #1 Lyman manual and it shows loads for the pure lead Foster slug, but nothing heavier. With 7625 a load of 38 grs is shown for over 1600 fps. I'm thinking of starting with 25 gr and chronographing. When I hit 1200-1300fps with good accuracy I'll stop. I've used .570 RB at 1250fps on lots of game including big muleys and have yet to recover one.

Could you describe what you mean by "patching". I'm trying to visualize how one would load a traditionally patched RB in a shell case. Your idea of using the cup from a plastic wad is something I thought I'd try in CBC brass cases. These measure .790" ID and need "something" to center the ball. May need to cut the cup from a 10g wad. In plastic cases, the ball is a snug fit. I plan to size .750 balls to .744 and use Lee liquid lube. May try unsized balls too, and let the forcing cone size them. Do you think at my velocity goal pure lead balls will shoot ok? I plan to try 1-20 alloy and WW, as well as pure lead. I'm thinking my 80" twist and .0075" deep grooves will handle soft balls just fine. If not, I'll harden the alloy. Think softer balls are most effective game loads, however.

Any/all advice is much appreciated.

Otto