Looking at using bottom end loads for the 45-70 Marlin 400 grain for a powder coated Lee 405 HB boolit. Probably H322 since that is my favorite powder in 45-70. 51.5 grains should give me 1750 FPS I'd say.
The other options are 3031 and 4064. Probably I'll try those first since I have a good bit of those powders.
Opinions?