Joe,
Your description of a scraper is precisely correct,for those used to scrape flat surfaces like machine ways,dovetails,etc.German( and I would guess Austrian,Belgian,etc) gunsmiths use a different type scraper,with which they fit curved surfaces together. They scrape front sights,rear sight bases,clawmount bases,etc.,to achieve a close fit before soldering.They typically make these from 3-corner files,and I suppose if they bought one, it would be like a "bearing scraper".I never saw one used on a rifle bolt,so I have no idea how the pattern was achieved.Scraping is just about my least favorite thing to do.
Mike
