I have a recent model of Smith Wesson M&P 15 22. It has a polymer rail, and factory-installed MBUS front and rear sights.
My problems is that when I tried to mount a 4x scope or a light-weight reflex sight on the polymer rail, the scope ring screws or the mounting screw of the reflex sight always get loose by half a turn, no matter how I tighten them.
I thought the reason could be the elastic nature of the polymer. However, the factory-install MBUS sights are fine on the rail. So I assume that the mounting screws need to be vibration-resistant, or with some kind of loctite.
My question is, will loctite solve the problem? If so, is blue loctite enough, or I have to use red loctite?
My problems is that when I tried to mount a 4x scope or a light-weight reflex sight on the polymer rail, the scope ring screws or the mounting screw of the reflex sight always get loose by half a turn, no matter how I tighten them.
I thought the reason could be the elastic nature of the polymer. However, the factory-install MBUS sights are fine on the rail. So I assume that the mounting screws need to be vibration-resistant, or with some kind of loctite.
My question is, will loctite solve the problem? If so, is blue loctite enough, or I have to use red loctite?