Brass shoulder rings after firing (Sav LRP 260)

[codemancode]

I could use some input on these brass marks. Just picked up a model 12 LRP in 260 rem and i think the chamber might be rough. Shot about 80 rounds through it and all the brass came out with vertical rings around the entire circumference of the shoulder. I couldn't capture a picture of the defect though it is very pronounced. I posted a crude rendering of the defect to give some idea.

The load:
Lapua brass (virgin)- Defect wasn't present going into the chamber.
140 Nosler CC
45g 4831

I should say that the rifles accuracy is just fine. It will hold .5 MOA with various handloads which is more than adequate for my standards. This being the case i'm not sure its worth sending back to Savage. Of course, if this is going to significantly reduce my brass life i would like to have the defect rectified. Will these ridges affect the way the should bumps during sizing?

Any thoughts?

 

[Scaevola]

Possibly reamer chatter??

If it's a factory barrel, it's worth sending it in and having Savage make it right. Lapua's 260 brass ain't exactly cheap, and I'd be willing to bet those machining marks aren't going to be beneficial to long case life.