Easy...Keep good records. Record everything. Powder charge, lot #'s, OAL, bullet weights & types, number of rounds loaded, number of times you fired the brass, gun used, you name it. How many times have you loaded something up and they've just sat there waiting to be shot. If you didn't record what you've loaded, how do you know what you're shooting, and more importantly, how do you duplicate it again?
bownut
