You know what. You also probably didn't use the hex key (allen key) where that hole is... Just tighten it and you should be good to go.
Not sure which size key you need but if you have one of those swiss army hex key things just try putting it in and seeing if it fits and just tighten that.
Again when you want to swap out flash hiders or something take the hex hey and loosen it then twist off the flash hider. If you don't you run the risk of breaking the flash hider or stripping the threading.
ಠ_ಠLess QQ more Pew Pew
READY TO >> RACE