How the AR 15 / M4 DI or Direct Impingement System Works
This video breaks down the Direct Impingement (DI) gas system of the AR-15/M4 platform. It details the function of the Bolt Carrier Group (BCG), gas tube, and gas key in cycling the action. The explanation covers extraction, ejection, and the role of the buffer and spring in absorbing recoil and chambering new rounds.









