Karl,

Congrats, looks like fun. I do not have a single shot 45-70, but do have the Socom and a Guide Gun. But I think that yes, toying with Socom bullets would be a great idea. You've probably figured out that if not running hard cast lead, you end up with a small selection of 45-70 bullets designed for levers, or a broader selection of bullets deigned for the win mag. The lever gun bullets are poor in the BC department, and the win mag are over designed for the 45-70.

Craig