I have been using a co-ax for a few years now but never used the priming feature on the press. I have always used a lee autoprime. Anyways, wanting to try somethin different, I was looking at it and was wondering when you adjust (I am not sure what the proper name ) for different shell sizes, how do you know when you are centered on the primer? There is 3 adjustments and I could see trouble if not lined up.