Barrel nut= red threadlocker and as tight as it will go!

[Klem]

First of all, WHY? Because it is in manufacturers interests not to have things come loose when sold as a complete upper.

Second, is it possible the upper receiver is damaged from this? Depends on how you isolated the torque. Did you clamp the barrel?


Is this thing doomed, or should I give it a try and see if it works? Give it a try and see how it groups.

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