I've hardly noticed powder type, or charge weight making a big difference in pistols and revolvers. Once in a while ,I would get a bad combo that was worse than my average loads. I would just not use that combo/powder charge again. Now in long range rifle, that's another world completely. I've had groups at 100y, go from 1 1/2", to 1/4" with powder charge weight and bullet seating changes. Once I get my 308 under 1/2" MOA,@ 100 yards, I'm good to go at 500Y and beyond.