I’ve hade my NX8 for about a week now. It’s taking a little getting used to but so far I like it. Wasn’t able to use the same .885 rings that I used with my NXS. Had to move to 1” because the stubby knob on the power select ring would hit the rail.
Like I said before the three bare actions I have here all measure .042-.045. The one I have built up measures the same and my primers look nothing like yours. Do you by chance have deep primer pockets?
I load 123 SMK’s (6.5) for my daughter to plink. Hunting loads are 124 HH and they both shoot the same out to 500 yards. Same powder charge and didn’t move my seating stem. The 123’s are .012 out and I have no idea where the HH’s are. It just works.