Before loading them, get an idea on the weight of the various cases.  I got a couple hundred REM-UMC, 30 USA once that appeared to be from two lots, weight varied by 30gr from lightest to heaviest.  They were once fired, and I could tell the heavier ones developed more pressure.  Looked like they'd developed their load in the lighter ones and loaded the heavier ones the same.  That caused quite a bit of expansion in the heavies.