Airsoft Tec demonstrates the homemade drum magazines they made for the KSC/KWA MAC11 M11A1 Gas Blowbacks... "I made a drum magazine for KSC M11. It is a form that diverts CYMA's Thompson drum magazine and forcibly combines it with a normal magazine. If the BB feeding goes well, you can shoot quite comfortably.

You can maximize its firepower by connecting it to an external source. You can enjoy the recoil that you can't experience with a normal magazine. The surface of the drum magazine is heated with gas to heat bluing to enhance the texture and give a better feel when handling it."