I figured I'd start a new thread. My SW mp15 will not cycle. It's a single shot. It all works fine manually, feeds, fires, ejects by hand but the bolt is not cycling when shooting. I would presume something blocking the gas system. I had some long ar gas tube pipe type cleaners and ran it thru with no obstructions. I'm not sure if it got thru the hole in the gas block though. The key mates up to the tube ok.Any ideas? Thanks.