Hey texgunner,I have taken apart all my Hatsan springer's more times than I'd like to remember . I've always laid the gun on its side, and with the largest & longest, straight screwdriver (I have) cranked the screw tight (sometimes using (yellow Harbor Freight) rubber gloves). To date, never had one loosen, never used loctite either Also, once the big screw is tightened, the Mini screw should keep the bigger on from moving. Sometimes I turn the Mini screw down using a file (in drill) to fit if in-between notches (re-blue after).My Two Cents.................... Good luck These little nagging things can be a big distraction if they get out of hand