This assembly consists of:
Gas Tube
Gas Block
Gas Tube Roll Pin
- AR-15 Inner Barrel Retainer Nut, Outer Receiver Nut, and Upper Receiver
Insert AR 15 gas tube into gas holes on inner barrel retainer nut, outer receiver nut and upper receiver. Make sure the end with the three holes (these are for the gas tube roll pin and gas hole going into the barrel) is on the end where the gas block will be.
- AR-15 Gas Block
Loosen set screws on the bottom of gas block so it will slide over barrel.
- AR-15 Gas Block
Slide gas block all the way onto barrel as far as it will go, guiding gas tube into hole in gas block.
*Note: You may have to polish the barrel where the gas block goes and polish the inside of the gas block with 600 grit paper so it easily slides in place. This only takes a minute or two.
- AR-15 Gas Block
Barely tighten set screws on the Gas Block so it will stay in place, but you can still rotate it by hand.
- AR-15 Gas Block and Gas Tube
Orient the gas block so the gas hole in the gas tube and the gas hole in the barrel are perfectly aligned.
Tighten set screws.
Drive gas tube roll pin through gas block and gas tube.
