My SAR-2 left an empty in the chamber and the extractor slipped over the rim.  I had to knock it out with a cleaning rod.  I replaced the extractor spring and slightly shortened the hole in the extractor to increase extractor tension.  While my quick rapid rife followed by letting a round set in a hot chamber for a couple of minuites followed by another rapid fire mag shows the problem did not reoccur, I am wondering:

The chamber has some rings in it, it is not baby-ass smooth like my Inrange Bulgy or my other SAR-2, should and how should I polish the chamber to help things a bit and should I even polish it at all?

What do you recommend for paste?  I.E. something I could find at Graingers