AR Gas Tube & Carrier Key Gauge
This video from School of the American Rifle demonstrates a practical DIY method for checking AR-15 gas tubes for internal obstructions. Using readily available 0.080-inch diameter weed whacker line, the instructor shows how to insert it into the gas tube to act as an internal gauge. This technique helps identify potential blockages from manufacturing debris, carbon buildup, or residue from certain ammunition types, ensuring proper gas system function.












