You might measure the base at the .2" line and make sure your chamber is in spec, I stuck a case first shot in my new 284 with a light load because the tail of the chamber was under spec from a worn reamer. Had to send it off to a different smith to be cleaned it up, now 52.4gr H4350 has zero pressure signs and shot brass flies in and out.19", 162ELDM, 3.131 coal, WLR, 52.2gr H4350. Peterson brass.
I will note that I am getting light clickers on the first firing but I didn't FL size the virgin brass so not gonna get too concerned just yet on that front till I set up the die for a proper shoulder bump now and see how things run.