If I were in your situation, knowing what I now know regarding Nosler brass, I'd shove the primer in there not worrying about variations in seating depth. As long as the primer doesn't extend above the case head there is nothing to be concerned about.
Work up your load heading towards maximum velocity. Long before you attain significant pressure the primer pockets will be opened sufficiently that your tool will fit with plenty of room. If you then do the ream thing you will be frustrated as way sooner than you would like the case won't hold a primer at all.
this has been my experience loading Nosler 300 RUM brass in a 270 Allen Mag. With Rem brass loads the Nosler stuff lasted on three shots compared to the Remmy's 5 or 6.
Sorry to be so rude but I think very little of Nosler brass when attempting to attain maximum reasonable performance.
Nosler's advertising/marketing sucks everyone in for a little while.