OK I initially loaded 50 gr of IMR4064 that shot pretty good. I made up some other loads with 49 gr and 51 gr of IMR4064 and another load of 45 gr of H4198. The 49 gr load shot pretty good but the 51 gr load was horrible and so was the H4198 load. I did notice before that the rifle is very finicky when the barrel becomes hot. So I would fire a 3 shot group and let it cool while I shot another gun. 49 gr shot right about 1.5" same as the earlier 50 gr charge. But 51 gr opened up to about 6". The 4198 wasn't too awful bad at about 2.5" but it was about 8" higher than my other loads.
Looks like I'll be staying with the 50 gr of IMR4064. I'm going to try one more thing and that's Hornady 300 gr jacketed bullets just for kicks. That's what I shoot out of my Guide Gun and My SBL. I really want to shoot cast bullets out of this 1895 Cowboy