the 45 acp headspaces of the case mouth,,to get good accuracy all cases need to be near exactly the same length,,and when you seat the bullet do no use much if any crimp..
I can ask Daddy what his routine was,,he has a Bill Wilson that he used in IDPA that he loaded in excess of 100,000 rounds for,
at 25 yards it would shoot 7 rounds in a hole that looked about like one 12 gauge slug hole.