In Paul a matthews book ‘ loading the black powder rifle cartridge’ he suggest starting with a bore size bullet and PP your favorite paper. Or patch up to bore size. I am going to try these bullets. Do a search on forum- black powder cartridge for other help for 43 Mauser. I am going to try a straight load of 3fg now too. Someone said that 43 Mauser is in the transition size between 2fg and 3fg- a bullet master.