I just recieved a complete upper from a very reputible distributor. Planning to change out the free float hand guard in the near future, I checked to see what size allen wrench would be needed to remove it from the barrel nut.

Turns out that I need a metric wrench. Does this mean that the part could have come from China like so many I see on e-bay?

I could wish a lot of things on my worst enemy but neuropathy ain't one of them.