Designation stands for Gryazev-Shipunov 23mm after its designers V. Gryazev and A. Shipunov.
This weapon was introduced in 1965. Its works after the so-called "Gast" principle which was invented in Germany during the First World War (1916, small series of 7.92mm and prototype of 13mm weapons being built) by Karl Gast at the Vorwerk company (today one of the leading producers of vacuum cleaners in Germany). A "Gast" weapon has twin barrels and the recoil from the firing of one barrel reloads and fires the other barrel via a lever mechanism. This system is simple, extremely reliable and makes possible compact lightweight weapons with a very high rate of fire (surpassed only by the much heavier and complicated guns with multiple rotating barrels). Despite these advantages the GSh-23L remained the only "Gast" gun built in large numbers until today.
At first this gun appeared on the second generation of the MiG-21. Here the GSh-23L was carried in a large GP-9 gun pod with 200 rounds of ammunition under the central fuselage. Later this was replaced by a much more streamlined semi-internal installation. Apart from fixed installations the GSh-23L can also be carried in a so-called UPK-23 pod (UPK: Unifitsirovannyj Pushechnyj Kontejner) on the external hardpoints of an aircraft.