PF Bartlien chamber...Cracking?

[Sticks]

A while back I noticed that I was getting a definitive ring, and longitudinal scratches in my fired brass just behind the shoulder in my PF Neptune VIII Bartlien upper.

I scrubbed the chamber, then ran a shotgun mop with some polishing compound in the chamber since I was still getting significant scratches in the case wall on fresh sized cases being chambered and extracted.

I also noticed that my fired brass was .008 (+/-) longer than normal - previous sessions.

I did a complete teardown on the upper to check for anything odd...that and my GB was canted and hitting my handguard.

I took it out for another range session and the ring was still there, and the longitudinal scratches came back, but it was a dusty day, so I wrote that off to just getting dust mix.

I obtained a Lyman bore cam and this is what I found. Is it me, or do those look like cracks? The left edge of frame is the transition into the shoulder.

[ATTACH=CONFIG]12234[/ATTACH][ATTACH=CONFIG]12235[/ATTACH][ATTACH=CONFIG]12236[/ATTACH][ATTACH=CONFIG]12237[/ATTACH][ATTACH=CONFIG]12238[/ATTACH][ATTACH=CONFIG]12239[/ATTACH][ATTACH=CONFIG]12240[/ATTACH]