OP-SKS: Hunting Carbine
By: Vadim Ribakov
From Small Arms Review-Vol. 4 No. 8, May, 2001

Born for battle in 1945, the SKS self-loading carbine was adopted by the Soviet Army in 1949. Simonov's brainchild proved reliable, rapid firing, and easy to operate. For maneuvering armies, the compact semiautomatic was lightweight and capable of delivering mid-range fire to a maximum distance of 600-800 meters. But aside from its battle worthy qualities, the SKS carbine was chiefly designed to utilize the recently developed 7.62x39mm ammunition round.
Dubbed "round sample 1943", the history of this intermediate cartridge and creation of Simonov's compact rifle go hand in hand. Previous attempts had been made to create or modify weapons based on the current 7.62x54R round, but the round itself was problematic. Too heavy, too powerful, its broad-rimmed case caused stoppages due to a failure to feed. Dissatisfied and embroiled in the Great War, the Army urgently sought an improved cartridge. An intermediate round with ballistics, mass, and dimensions that lay between the 54R and 25mm pistol - the basic calibers at the time.
In 1943, NiM. Elizaroy and B.V. Semin designed the 7.62x39mm round to fulfill the needs of the troops. With a bullet weight of 7.9 grams (122 grains), the steel-cored conventional ball had a maximum range of 1,000 meters. Design of mid-velocity (735 meters/second / 2411 fps) gave the round an inherent arched trajectory. During testing the bullet was fired into, and successfully defeated, three pine boards, each board 2.25cm (1 inch) in thickness.
The emergence of the 7.62x39mm broadened the development of new firearms. Reducing the rim to equal the diameter of the cartridge body simplified the construction of a feed mechanism. The lighter round also produced less recoil, thus improving accuracy and marksmanship. These benefits enabled S.G. Simonov to produce a carbine based on his 7.62 caliber semiautomatic rifle, the AVS-36. Upon meeting all requirements, the Soviet Army adopted the Simonov SKS. Other designs utilizing the 39mm appeared, most notably the Kalashnikov AK (avtomat Kalashnikova). The AK possessed similar ballistics, but had better battle qualities and soon replaced the SKS. Despite Simonov's modifications, production of the SKS ceased. Stockpiled in warehouses, the mass produced SKS slowly made its way onto the shelves of local gun shops and into the hands of Russian hunters. Eventually the Government interceded; passing a law that banned the military weapon from citizen possession. To meet the demand, the OP-SKS carbine was released for broad distribution.
Designated "OP" for the hunting trade, the semi-auto battle variant boasts minimal alterations. The bayonet and bracket hardware was removed. An identification "pin" was implanted in the barrel. Protruding above the grooves, this bit of metal scores a unique mark on every fired round. This notch is a specific identifier of each hunting carbine. The original "battle condition" SKS remains widely available on USA and foreign markets.
The uniform single-piece stock is constructed of birch or multi-layer plywood. The diminutive size of the carbine is designed for the average person, with an allowance for heavy outer winter wear. Installing a rubber shock absorber (recoil pad) can easily increase length of the butt stock. A removable bracket is required to mount optics.