04-12-2021, 01:06 PM
Bill Alexander used blue loctite on his barrel nut thread assemblies for ease of manufacture, to offset individual rifles that couldn't meet the 60 ft lb min barrel nut torque he recommended for the 6.5 Grendel. I use blue loctite on the threaded spring detent retaining screw, "for the rear take down pin behind the back plate" I install on every receiver I build. I use blue loctite on, trigger guard screws, receiver tension screws, barrel bedding, hand guard screws, etc. I have used red loctite on gas block mounting screws, but have switched to Rocksett. I use green loctite"620" between the barrel and gas block block journal for proper seal, barrel bedding, between the gas key and bolt carrier instead of Permatex aviation gasket compound and to seal gas tubes to gas blocks. Using loctite on the lower receiver extension "buffer tube" is not necessary if the threads are manufactured properly on the receiver and buffer tube, castle nut torqued to 38 ft lbs and staked properly. This is why I use Vltor buffer tubes exclusively. If the threads are sub standard, I use Vibra-tite VC-3 on the buffer tube threads before torquing the castle nut and staking. Using a torch to break down any loctite thread lock adhesive is a very simple process, if it becomes necessary..It could be quite possible to find AR builds, "where loctite has been used" if the AR was built by another person or manufacturer.. No need to panic..