I have a .380 auto handgun which uses a #8-32 NC cap-head screw to retain the trigger guard. During firing, the mechanical shock of the cycling action serves to rapidly loosen this screw regardless of the torque used to tighten it down. I cannot use a standard star washer because they're larger in diameter than the screwhead (there is no clearance between the rear of the screwhead and the trigger guard front) and split-ring lockwashers are useless. This screw must be removable because breaking down the weapon for cleaning requires removal of the trigger guard to disengage the slide, so permanent adhesives like certain types of Loctite are right out. Are there any thread locking devices which might serve the purpose? Thanks in advance.