Huggett Moderator experience

 I was set up on my brother-in-law's porch to snipe starlings out of his garden When I noticed my POI going lower and lower....and lower, what the heck! I am still at 200 bar. I found it to be where the caulking arm attaches to the action bar. I'm not sure if I'm calling this the right thing, it is the bar that seems to push the pellet probe forward. There are two small set screws that had loosened and the clasp was just sliding back-and-forth on the rod. The consequence being not seating the pallet the same every shot .