I have a .50 cal. CVA Kentucky pistol and the manual from CVA says minimum of 20 gr. 3F and a maximum of 60 gr. 3F. Personally I think 60 gr. would be a bit too much. I think I did 50 gr. of 2F (only powder I had at time) once, hard to hold onto. I normally shoot 20 - 30 gr. of 2F. I recently acquired some 3F but haven't tried it yet, guess its time to do a test.