Quick Tip: Where Should I Use Loctite on my AR-15?
Thread-locker, most commonly known by the Loctite® brand name, is a lot like a Dremel® tool: if you have it, you feel an almost overpowering urge to use it - a lot. "But wait," say Brownells Gun Techs Caleb and Steve, "go easy with the Loctite on your AR-15!" It should NOT be used where steel and aluminum parts are threaded together. The steel is hard and the Loctite, when compressed into the threads, is also hard. The softest material in this equation is the aluminum... and you run the risk of stripping the threads on the aluminum part. So DO NOT use Loctite on the castle nut / buffer tube connection or the pistol grip screw. (Some aftermarket AR-15 pistol grips DO come with material to put on the grip screw, but it's not Loctite.) What about the barrel nut threads? Nope, says Caleb, Loctite is not a replacement for applying proper torque to that nut. Muzzle devices get so hot that Loctite won't be able to do its job on them. Instead, use Rocksett™, which can handle temps up to 1,300 deg. F. Some manufacturers of low-profile gas blocks do recommend a dab o' Loctite on the setscrews, but again it's a high-heat area, so there's little-to-no benefit. Bottom line: Loctite is a great product... Just don't use it on your AR-15. Agree? Disagree?
WARNING: Never attempt to disassemble or reassemble a firearm unless you are absolutely certain that it is empty and unloaded. Visually inspect the chamber, the magazine and firing mechanism to be absolutely certain that no ammunition remains in the firearm. Disassembly and reassembly should follow the manufacturer’s instructions.