Loaded some 530 grain cast for my Sharps rifle. I went with a known accuracy smokeless load and it did very well. We are having horrible winter weather right now so might be awhile to confirm this load But looks promising.
The Pedersoli Sharps 45-70 I had for a while shot Swiss black powder very well with my 530 cast bullets...Lyman mold.
It was fun to crank the peep way up and hit rocks at 700 yds too....the furthest I could get out of the black powder fueled 530 gr bullets with the sight that came on my gun and went up 1.5" or so.
I played around some with the Sharps for a couple years then moved it on as it was not my passion. Still have the Lyman mold and 45-70 dies.