Anti-walk Trigger/Hammer Pins
The torque spec on the screw is 11 inch/pounds maximum; 8 inch/pounds of torque are recommended.
The .1555 diameter pin is for worn receiver trigger and hammer pin holes.
Note: The external width of some AR receivers may vary in the trigger/hammer pin area depending on the manufacturer.The pins may be shortened a small amount by carefully filing material evenly from both ends of the pins. Them being too long will not affect the function or performance.