If you fit things right you will not need loc-tite!
Im not a gunsmith, but I am a machinist and engineer. Listen to the words of Harry B..
I have often thought that you should need a license to buy Loctite. Believe it or not most people should be using grease or never seize where they are using loctite. To properly torque a screw you need lubrication. Properly torqued screws do not loosen. Consider loctite like a weld. If you wont weld that part dont loctite it. If you have vibration issues there are tacky products that dont harden which work much better than loctite. Also deformed thread screws, class 1 fit screws and nuts.
Dont believe me, check the machineries handbook.