In my Marlin Cowboy 20 inch 44 mag. I have not had any luck with the Lyman 429215 SWC. My mold cast to small and it has to be beagled.My rifle needs .433 to shoot accurate and a boolit no heavier than about 265 grains.My boolit of choice in a Accurate made mold is a 43-230C that cast .434 from ACWW. I size at .433 and use a aluminum home made gas check.Using 10 grains of Unique it shoots better than I can hold using a tang site.