PF Bartlien chamber...Cracking?

[Sticks]

Do wonder is this something you just started seeing after shooting about 1000 rounds?

Yes Mark, this is new. Rifle fired brass stayed consistent at 1.217-1.218. Out of nowhere I got a lot of vertical scratches that I presumed was dust getting in the chamber and the ring showing up just below the shoulder. Measurements on those when it showed up was 1.225 (going off memory here measurements from case to shoulder datum may be 1.125 - I know it was a .008 growth).

Another thread on it when I asked if my chamber could be stretching or something. The thought was that I might have a been over gassed and the bolt was unlocking too soon allowing the brass to stretch more. This is what prompted the complete teardown, inspection (pre-bore cam), lapping the receiver, bedding the barrel extension and gas block. Test firing for tuning still showed the scratches and ring, then I polished the chamber with a shotgun mop and lapping compound until scratches were no longer present from simple new sized brass being hand fed. Warranty is a little expired now.