I have a batch of 6XC brass that I skimmed the necks just to clean them and while reloading them I'm finding a few with really tight necks. All are new never fired, I lubed and resized them all, run them over my neck mandrel and skim turned them. Loading 25 yesterday I found 3 that took excessive force to seat bullets.
I have also come across this with my 22BR brass.
I have also come across this with my 22BR brass.