Ongoing issues....extraction/ejection?

[browningautorifle]

I'm guessing an "aftermarket" barrel:

Bruce, this is the one he had a long thread about replacing the barrel. It's brand new...

sanding sounds a bit intimidating.
This is the area we are referencing with the "concentric" circles"?

Yes, that was what I was talking about. If worried then a gunsmith can do a chamber polish, it should be his bread and butter. Like Cinders says, a drill on low and steady with a mandrell of wood dowel and paper around it, wrapped opposite to the spin. Light oil but oil it for sure. Just do a few seconds and clean and examine. You'll see a difference. A gunsmith could do it in minutes, but shouldn't have you watching...that's when things go wrong for sure. It really is simple to do...fine machine paper.