I talked with Bunny at Compass Lake a couple of days ago, and she gave me some unusual things to check that it could be. When I checked one of them, the diameter of the bolt stem, I found that it was undersized by pretty close to .010". It seems that after I popped the primers at the National Matches, I cleaned the $h!t out of the rifle because of the carbon from popped primers. It seems that I probably cleaned the tolerance off of the bolt stem while at it! I will replace at minimum the bolt and also the bolt carrier, in case I cleaned that too well, also. This cleaning seems to be what made the rifle start to malfunction "while it was in the safe", and also why none of the regular fixes had any effect, but I won't be sure till I try the rifle in the spring.
Danny