I have seen this one before. A gun is put together without the rear edge of the chamber "broken" so that it does not leave a sharp edge that can scratch brass or impede smooth chambering. Ideas on a fix without taking the barrel back off? 340 grit wet on my fingertip? Small piece of soft stone on a popsicle stick?

A stick with the end tapered about 45 degrees with that grit on it should help. I suppose a wood dowel would be neat but you must have some free, straight branches in NY.

Then drill a hole sideways thru the other end and put in a dental roll in there and clean out the bolt recesses in the action. Sinclair and others sell a device for this but the wood seems even better.

take a toilet --little work... cute word--- paper roll, fold it in half (so the diameter is smaller) wrap in 340, 400, whatever, jam into just the barest end of hte chamber, and lightly twist...

if such a thing bothers you
jeffe