So i'm building my first full AR and I was just reading about someone having trouble getting the barrel nut on tight enough to get the gas tube through. So I came across the same issue and instead of waiting until tomorrow to take it someone and have it done right I get all impatient and try to hulk it myself. So now I have a nice idiot mark on my flat top rail!! Ugggggghhhhhh!!! Why?!? Now I have to go to bed angry. Not sure why my pics come up upside down.