I think I may have fixed the problem. Either the cleaning and lube job on the trigger, piston and compression chamber is starting to take effect, or the additional lubing I did last night on the middle sear spring took care of it. Still having the issue once in a while, but it seems to be going away.As near as I can tell: Either the piston was sticking and not releasing from the lack of moly, or the middle sear spring was binding on something.By the way, I like both my D34 and TX200. The D34 is my go-to rifle for pest control: One day I took out 3 pest is 90 seconds when I used a pellet pen for reloading. The TX200 is my Field Target gun: Deadly accurate and able to produce dime-size groups out to 40 yards, but a little too heavy for off-hand shooting, and awkward to reload for those follow-on shots.