The Saiga-12 () is a shotgun available in a wide range of configurations, patterned after the Kalashnikov series of rifles and named after the Saiga antelope native to Russia. Like the Kalashnikov rifle variants, it is a rotating bolt, long-stroke gas piston operated firearm that feeds from a box magazine. All Saiga-12 configurations are recognizable as Kalashnikov-pattern guns by the large lever-safety on the right side of the receiver, the optic mounting rail on the left side of the receiver and the large top-mounted dust cover held in place by the rear of the recoil spring assembly. Saiga firearms are meant for civilian domestic sale in Russia, and export to international markets. The Saiga-12 is manufactured by the Kalashnikov Concern (the merger of Izhmash and Izhevsk), in Russia. Kalashnikov Concern also manufactures Saiga 20s and Saiga 410s in 20-gauge and .410 bore, as well as the Saiga semi-automatic hunting rifles in a number of centerfire calibers. Russian armed forces use a combat shotgun variant called the KSK (Karabin Spetsialniy Kalahnikov, "Kalashnikov Special Carbine"), with the 12-gauge size expressed in its metric equivalent of 18.5 mm. The Picatinny rail layout is similar to the civilian 030 version. Modifications to the basic Kalashnikov pattern The Saiga-12 incorporates several features absent on the Kalashnikov and its derivatives. Since shotgun shells are nearly twice as wide as 7.62×39mm cartridge, the extraction port in the side of the dust cover had to be increased in size. However, since the bolt had to remain the same length to fit inside the AK-47 sized receiver, the rear section of the bolt is covered by a sliding metal flap that rides on the recoil spring. This allows the gun to be sealed against dirt when the bolt is forward, but the compression of the recoil spring during firing moves the flap rearward to clear the extracted shells. For the likely reason of simplifying production of Izhmash's other Kalashnikov-pattern guns, the Saiga-12 extractor does not rotate, but instead delegates the bolt-locking function to a caliber-neutral lug directly behind the bolt-face. The Saiga-12 incorporates an adjustable two-position gas system, with "standard" and "magnum" settings for firing 2-3/4" and 3"-length shells respectively. This is because firing 3" shells with high power loads such as slugs and buckshot generates so much force that the receiver will be damaged if the full power of the gas system is employed without some sort of