I'm not sure about older bolts, but mine has a teflon like coating that I'm pretty sure was put on there for a reason. Seems like polishing it off might be counterproductive down the road.
Looks like a Rock River. If you look around you will find that quite a few other folks have had the same problem and apparently RRA does not recognize it as a warranty repair.
Just wanted to say hi. Long time gun owner and lurker. New to the forum. Looking forward to meeting some of the great folks whose posts I've been reading. As a ny state resident (until my house sells) I hope we can all do our part to reverse some of the frightening assaults our constitution has...