Originally manufactured in 1981 by Heckler & Koch as a semi-automatic rifle, this rifle was upgraded to HK51 configuration and registered per the National Firearms Act by Fleming Firearms, turning it into an extremely compact high power selective fire weapon. Hooded post front and 4-position drum rear sights, with a slotted birdcage flash hider on the "IBMC" barrel, textured plastic forearm, textured pistol grip and two position telescoping buttstock with checkered buttplate. The shelf pattern receiver bears the "HK Inc" import mark, "IB" date code, and remarked "HK51" model marking on the magazine well, and the Fleming Firearms marking on the right side, concealed by the trigger housing. The housing is "0/1/A" marked, and fitted with a shelf-pattern trigger group and right handed switch. The bolt and bolt carrier are both "IB" dated, and the carrier shortened and modified for sear compatibility. With six extra magazines, a padded sling and a black canvas soft case.