yes, what Mike said.

Almost finished my response when the phone rang and I got distracted, here it is anyway fwiw:

85lc:
I'm sure you will have already considered this, but in bottle-neck cases with a relatively well defined shoulder like the 500/450 it is a simple matter to head-space on the shoulder, in which case rim thickness becomes irrelevant.

Obviously you are making your own cases so setting the perfect tolerance for your rifle should give better case longevity than relying on rim thickness consistency from some of the donor brass manufacturers.