My 500 gr cast bullet load is with 62 grs BP,recoil is not bad at all because of the weight of the Shiloh Sharps.
I have never used jacketed or smokeless powder loads in the Sharps as I feel that the 45/70 was originally a BP cartridge.

I would imaging that the Marlin 45/70 lever action rifles would have a bot of recoil with some of the loads available out there.

Wayne