Thank You, Jim Keehan, for prompting me where to look; there is nothing wrong with the extractor, but it turned out that the previous owner, in trying to MAKE IT ACCEPT A DIFFERENT ROUND had " thoughtfully" ground off the supporting ring. ( I must say, though, he did a reasonably neat job, so that I didn't notice it at first). My friend is now ordering a new bolt center from Gun Parts Corp.again, thanx.
paranoia is really the only SANE outlook when about 50% of the U.S. Senate is out to get You!