The G3 is a select-fire battle rifle developed in the 1950’s using 7.62x51mm NATO rounds. The G3 is a selective-fire automatic weapon that uses a roller-delayed blowback operating system. The HK91 is a redesigned HK41, which is a semi automatic version of the G3, and was produced for the civilian market in the 1960’s. However due to an import ban in 1989 by President Bush, few HK91s made it to the U.S market. As a result, the HK91 remains valuable to collectors today.