When I torque the barrel nut, I torque it, loosen and re-torque 2 more times. A co-worker says to use some special grease on the threads, any truth to this? I have never had a problem, but consider myself a shade tree gunsmith. Always open to learning.
If it is gonna be a range gun, and you want to build and not buy complete, buy a little at a time while buying more ammo. The 2nd does not protect ammo, so eventually they will go after that.