Should the gas tube be centered in the barrel-nut notch, or is it acceptable for one side to be touching the tube? I just received a new upper and when looking it over, I noticed that one side of the gas tube was touching the barrel-nut notch. I inserted a small thin piece of paper and verified that it is touching on one side. The gas tube looks straight in the receiver. I can’t remember from my last armorer class if this was acceptable or not. Thanks in advance for your assistance.
Remove the bolt carrier from the weapon. Remove the bolt from the carrier. Reinstall the carrier and let it slide home. Does it hit the gas tube? If not, it should be straight and not give you any problem. If it does hit, it may be because of the contact with the barrel nut and will need to be fixed.
-RD62
As long as the gas tube does not have undue stress on it and it is straight in the upper rceiver and not hitting (binding) on the bolt carrier key, you should be GTG.
Just went through a similar issue myself involving the gas tube and barrel nut.
In my case the gas tube and key alignment were off.The gas tube was not bent/formed properly causing it to bind on the underside against the barrel nut.
I had to bend the gas tube to get the proper alignment with the gas key.
Up until that point in my life I had no idea how robust the gas tubes actually were.Always treated them like they were fragile.
Is there a special tool available that helps in bending/tuning a gas tube?