Gunsmithing Brass marks

[MWDG3]

Can some educate me as to what these rings and marks mean?

It's Federal 7.62 Match. Once fired.

 

[Mark Housel]

Re: Brass marks

They appear to be due to rings in the chamber itself.

I'm supposing that the brass didn't have these marks before being fired.

Did this rifle always do this to the brass?

 

[turbo54]

Re: Brass marks

Looks like a chamber needs some polishing...

 

[Shortdraw]

Re: Brass marks

Definitely a rough chamber.

 

[MWDG3]

Re: Brass marks

This is what I'm afraid of, thought I'd run it by you guys. Its a DPMS LR308 with a Howa heavy barrel. Very first trip to the range with the new barrel, first case stuck in the chamber and me without tools. Needless to say I wasn't thrilled. Stuck case was a surplus NATO intended as a fouler.

Second trip with tools and Federal NATO match cycled flawlessly. But the rings on the brass threw me. I still need to do more work grouping, but I will contact the gunsmith for his take. It was fun dinging 100yd steel offhand with a 12lbs AR.

Next trip I try 300.