Buttstock question

[lysander]

Learned something new today. Had always assumed it was the swipe stick version of Loctite.

You were both sort of right the first time. At least for Colt screws, made per the drawing.

It's a Nylock brand medium strength thread locker, pre-applied to the threads, not the usual nylon button inserted in the threads-type nylock fastener.

Other brands may use other type pre-applied threadlockers.

[LMT/556]

Movement in my LMT A2 lower was eliminated by tightening with an impact driver slot head in a 3/8 in ratchet while applying enough force to keep the driver in the slot. It takes more torque than practical through even a large screw drive.