Pappy,
Have you measured the brass in a few places? Lapua brass is made to CIP specs rather than SAAMI specs. It's a tad larger in diameter at the .200 line. Maybe at the rim too?
Just checked some new Lapua 22-250 rims against some unfired '90s era WW brass & the Lapua is right around .470" +/- .003 while the WW brass is around .465" +/- .002. Some unfired Nosler brass measures .465-.468", while PPU (CIP specced) measures around .466-.470".
Just a thought... a small amount of crud build up in the corners of a snug bolt face might be problematic, or judicious polishing of the rims could help some.
