[Richard Flanders]

Dave F: I've seen that a few times and if the screw is truly bottomed out and in the recess in the extractor, I just file the end of the screw until it no longer binds and goes in tight enough to stay there. Better to file the screw than the extractor rod, tho I have done that also if it was chewed up by the screw. Make sure there's nothing buggered about the threads that is causing the issue before you do anything. It may be a replacement screw. Other option is the aforementioned loctite but I'd use the medium strength blue not the red and make sure you clean the screw and the threads in the bbls with starter fluid or alcohol before applying the loctite or it won't hold. Sometimes I just clean the threads as above and use some blue or hi-temp red silicone seal to hold them. That works also and is guaranteed to hold but come out easily when you want it. That retainer screw should be nicely flush when snugged up if it's the original screw.