The G3 served as a basis for many other weapons, among them: the PSG1 and MSG90 precision rifles, the HK11 and HK21 family of light machine guns, a semi-automatic version known as the HK41, a "sporterized" model called the SR9 (designed for the civilian market in countries where the HK91 would not qualify, primarily the US after the 1989 importation restrictions) and the MC51 carbine.