1.) Squaring your dies
2.) Deprime in separate operation
3.) Move expander ball as far up as possble in sizer after depriming in sep operation
4.) When seating bullets, raise ram up to touch sizer and then back down to center brass. shell holder slop is #1 reason for bullet runout.
5.) After centering brass in shell holder, rotate brass 1/3 turn at a time and do not seat in one operation.