I have an L.C.Smith 12 ga. w/ the SST option, that does not work properly (I understand this is fairly common)...I disassembled the gun, and found that the "safety" leg wobbles from side to side, and misses the trigger mechanism occasionally (does not engage properly)...also, the whole trigger mechanism is movable side to side...Can this be shimmed to correct? All the screws are tight. Thanks for any information.