There was an article awhile back that dealt with reduced 45-70 loads. I couldn't find it so at the risk of redundancy; here's mine.
45-70 cases mixed lot, cci LR primers, 30grs. FFG, and 2 .460x.5" fiber wads from buffalo arms. This is a compressed load but the fiber wads compress easily and I needed to use up almost that amount of space anyway. It was down right pleasant to shoot but still had some kick, about like my '06 with a 220 grn bullet ahead of 30 grns. 4895. Works better than just really deep seating of the bullet.
My 1873 springfield is not real accurate anyway so I was happy with soup can accuracy.