H&K G3 assault rifle 20 round light weight aluminum magazine. These magazines were used by the German military until the G3 rifle was replaced with the H&K G36. The H&K G3 rifle is the rifle that put Heckler & Koch on the map and continues to see services throughout the world. With the long distance stopping power of the 7.62x51 round and the legendary reliability of the H&K roller-locked system, security professionals around the world recognize the G3 for the capabilities it brings to any environment.