There's been alot of that going around here lately..

I have a Purdey hammer gun that has individual lock plate screws after extensive shooting at the range I noticed them loosening up...at the advice of someone that knows more than eYe...I took them out cleaned the 'heads of the screws'...and the 'holes' in the lock plates real good with Acetone.
I then put a little Super glue on the 'sides of the screw heads' not the threads and screwed them back in...they haven't backed yet.