My favorite load for my 45-70 Guide Gun is 56.0 grains of H335, CCI 250 primer, and the Hornady 350 grain Interlock Flat Point. Velocity out of the Guide Gun is 1800FPS, and groups are one ragged hole at 50 yards.
Recoil is moderate. I'm going to be trying the same load, but with a Oregon Trail Laser Cast 350 grain Flat Point in the next few days...