Earlier this week, I shot some loads in my 26" CBI .260 barrel with virgin Lapua brass in what has proven to be fairly mild in Nosler & RP brass...123 A-Max with 39.0-39.6gr Varget. I experienced some decent pressure signs; pancaked primers that looked to slightly be backed out and cratered primers, slight sticky bolt, and light ejector swipes on a couple cases.

Never seen any pressure with these loads using RP or Nosler brass.

Threw this question up over on Sniper's Hide, and a few folks there think I may not have enough clearance in my chamber to use the thicker Lapua brass without neck turning, which is causing this issue.

So...anybody know the chamber dimensions of Criterion's 260 reamer (Jim?) or experienced similar pressure signs in their 260 CBI with unturned Lapua brass?