Shim may be tricky with the trigger guard but should work fine on any action screws.
I've made an unconventional repair to a guard once where weld was run around the countersunk part then I used valve grinding paste to lap the screw back in after rough shaping the angle . Professionals may cringe but I used a cordless drill to carefully spin the screw until it sat at the right depth and could be timed.

Last edited by El Garro; 05/25/17 02:06 PM.
Rust never sleeps !