Originally Posted by Cole125
Loc tite is necessary on the buffer tube castle nut if your not going to stake it. It's also necessary on back up iron sight screws.
As said above, NO NOT use it on the barrel nut.
If you have a low profile gas block, send the barrel/gas block to ADCO and get it pinned. Even with set screws it can and will move making your rifle useless.
My current lower setup is the only one I have ever had staked, and none of the previous ones had thread locker on them. They WERE torqued to spec, and not a single one ever came loose, even when they were run hard.