I'm just curious if anyone has tested 30-378 loads that are identical with the exception of the brass. I have some once and twice fired Weatherby brass and some brand new Norma brass. I'm about to do some load testing and am wondering if this should be a variable or if there is negligible difference. Should I expect these to hit in the same location provided primer, bullet, powder, case length, and everything else is kept constant? Merry Christmas!