Two nights ago I loaded my first 13 rounds of 45-70, getting ready for bear season August 10th. I used Starline brass, WLR primers, and loaded 3 shot groups with 57.0gr, 57.6gr, 58.2gr, and 58.8 gr of IMR 8208 XBR. Loaded one fouler at 56.0gr. They all shot minute of bear at 100 yards but I think I've settled on the 58.2gr load, it shot ~1.5" at 100 yards. I tell you what, shooting the 45-70 on the bench without a lead-sled is pretty punishing. I had entertained the idea of working up to 61.0gr and seeing what kind of accuracy I can get but I think 1.5" is good enough
I also resized, tumbled and primed 50 pieces of 50 Beowulf brass last night.