Best way to polish chamber

[tobnpr]

This one isn't getting "polished" out...
Just came in, brand new factory Savage. Quite puzzling...

[ShootistPRS]

Time to give Savage a call on that one!
You have to give the manufacturer a chance to correct their QC by letting them know when they screw up.

[Unclenick]

Glad the flex hone worked for you on the original problem. Flexhone points out (you can look up their YouTube videos) that these fine hones don't change the chamber diameter appreciably. Instead, if you were to look at a profile of the tool marks under magnification, you would see jagged mountain-like profiles, and the hone cuts off their peaks. The valleys remain to some extent. But you can actually reduce the ring appearance a bit further by getting some 800-1000 grit lapping compound and going in with it on a soft cloth and using your finger to polish all around the inside of the chamber. A bore mop on a drill would probably be fine, too. The more pliant material tends to round the edges of the cut off peaks a bit more than the hone does. Just be even all over and don't go heavy with it.

That Savage looks like a piece of sharf pushed the shoulder corner of the finishing reamer against the chamber in one direction during withdrawal from the cut chamber. Send them the photo and the barrel. I'm sure they'll fix it.

[tobnpr]

Time to give Savage a call on that one!
You have to give the manufacturer a chance to correct their QC by letting them know when they screw up.

Called Savage- about useless. "Send it back and our technicians will diagnose the problem", probably read from a book. My head was steaming...explaining that I am a FFL/smith and KNOW what the problem is, made no difference. Could not talk to a tech.

I'm setting back the breech/re-cutting the chamber (6.5 Creedmoor) for the customer, he didn't want to wait however long to get it back from Savage. I'd had it here for a while for bedding/receiver truing and don't blame him for wanting it back. I didn't even know there was an issue until I test fired it after re-installing the factory barrel and could barely get the brass to extract.

That Savage looks like a piece of sharf pushed the shoulder corner of the finishing reamer against the chamber in one direction during withdrawal from the cut chamber. Send them the photo and the barrel. I'm sure they'll fix it.

That's what it looked like to me initially. But, seems the "threads" are running the opposite way from what you'd get from a CCW rotating barrel.
I can't come up with any other explanation though.