The retracted pin indicates a stuck cocking hook mechanism that is not retracting to release the barrels.
Soak the end of the pin with Breakfree CLP and also apply the CLP inside the receiver at the bottom of the trigger plate front.
Be patient and eventually the CLP will disrupt the crud and rust "freezing" up the mechanism. When the pin starts to exit the receiver front gently assist its exit adding more CLP.
Bob Jurewicz
|