To sidestep the United States assault rifle ban of 1989, Heckler & Koch of West Germany took their HK 91, based on the HK 41 semi-automatic rifle, and reworked/rebranded the product as a sporting and target rifle to become the "HK 911" and then the "HK SR9" (in 1990). Changes to the original included loss of the separate pistol grip, flash suppressor and bayonet mountings - the more common traits of an assault weapon. A shortened, lighter weight barrel was installed and, in 1994, magazine counts restricted to five rounds. Fire was limited to semi-automatic only. Both wood and polymer (black) stocks were eventually featured in the product line.
Overall weight of the rifle was around 11 pounds. Dimensions included an overall length of 42.5 inches with a barrel measuring 19.7 inches long. The weapon was chambered for the 7.62x51mm NATO cartridge firing from a 5- or 20-round detachable box magazine (using a straight box design) through a double-column, spring-loaded approach. The action remained the HK roller-delayed blowback system of operation with a semi-automatic firing function. Sighting was through a standard iron arrangement or optics mounted over the receiver in the typical way. A long-running forend allowed for a landing area for the supporting hand under the barrel with the barrel protruding a short distance ahead of this assembly. The weapon used the traditional HK selector switch near the firing hand's thumb, color-coded for quick recognition.
Two major variants of the SR9 were developed - the SR9T ("Target") and the SR9TC ("Target Competition"). The Target model incorporated the shoulder stock of the MSG90 rifle with an integral thumbhole and the precision trigger group of the PSG-1 sniper rifle was borrowed. The Target Competition model added the PSG-1's adjustable shoulder stock unit while retaining many of the elements seen in the Target model.