The KS-23 (Karabin Spetsialniy 23mm, Карабин Специальный 23мм, 23mm Special Carbine in English) is a Russian shotgun.
After the Soviet government cancelled the purchase of certain ZU-23 machine guns due to manufacturing flaws, the Soviet government decided to recycle the barrels of the ZU-23s. It has been in service in various counter-terrorist groups in Russia since the 1970's, including the MVD, FSB (KGB), Spetsnaz and the Russian Ground Forces, though it is being replaced by the Saiga 12K in the RGF. No other country has been reported to have used the KS-23, but some ex-Soviet nations are reported to have KS-23s in their arsenals.
The KS-23 is a pump-action shotgun with a rifled barrel. Its bolt has four locking lugs. In spite of the weapon being a shotgun, the KS-23 is classified as a carbine in Russia due to its rifled barrel.
The KS-23 is well known for being the largest caliber shotgun used in service with any country. The round it uses, the 23x75mmR, is the largest known shotgun bore round to be used with any military; this equates to about 6.27 gauge using current British and American standards, or 4 gauge using current European standards.
- KS-23 - The original version.
- KS-23M Drozd - Variant with detachable wire buttstock.
- KS-23K - A bullpup version of the KS-23 that uses a detachable box magazine instead of a tube magazine.
- TOZ-123 Selezen - Civilian market version of the KS-23, featuring a smoothbore design instead of the rifled barrel and is chambered in 4 gauge instead of the normal 23x75mmR shells.