I have used a number of powders all with good results.
RL7, H4198, IMR3031, H4895, Varget, Benchmark, AA5744, Trail Boss. I have loaded both 350 grain FP and RN and find they both shoot accurately out of my Marlin 1895. My favourite loads however are with a home cast 405 grain FP water quenched and driven along with either a light charge (12 gr) of Trial Boss for about 970 ft per second, or 25 grains of AA5744 for about 1300 fps - close to the original load.
My experience is that a almost any load seems to shoot well out of 45-70, and even the water quenched cast bullet penetrates deep.
Have fun and enjoy this classy old gal.
