I just purchased a used Browning 1885 .45/70 B.P.C.R. and I want to shoot smokeless in it. I have one just like it that I shoot in competition but use Black Powder in it. I occasionally like to have a gun for a "newby" to shoot that does not require so much cleaning. I want to use a powder that comes close to filling the case. I found that I could put as much as 49.0 Gr. of I.M.R. 3031 in the case behind a 480 gr. lead bullet without using a wad. I do not want a stout load, but an effective one. I have loaded up some rounds with 42.0 gr. , but wonder what kind of flexibility I have with that powder.