I seem to recall in one of the Video tapes on customizing mausers put out by AGI that they fixed some pitting on some of their bolt faces by making very tiny welds to fill in the pit, and then of course dressing it off. I don't know anymore about it than that, but the video of them doing it sure looked good.
Maybe you could find somebody locally that is set up for micro tig welding and give it a try.
