ZU - 23 - 2 The ZU - 23 - 2 " Sergey " , also known as ZU - 23 , is a Soviet towed 23 mm anti - aircraft twin - barreled autocannon . ZU stands for " Zenitnaya Ustanovka " ( Russian : Зенитная Установка ) - anti - aircraft mount . The GRAU index is 2A13 . Development history . The ZU - 23 - 2 was developed in the late 1950s . It was designed to engage low - flying targets at a range of 2 . 5 km as well as armoured vehicles at a range of 2 km and for direct defense of troops and strategic locations against air assault usually conducted by helicopters and low - flying airplanes . In 1955 , KBP presented the single - barrel ZU - 1 and the twin - barrel ZU - 14 . While the former was eventually dropped , the ZU - 14 was selected and , after some modifications , entered series production . In the Soviet Union , some 140 , 000 units were produced . The ZU - 23 has also been produced under licence by Bulgaria , Poland , Egypt and the People ' s Republic of China . Development of this weapon into a self - propelled anti - aircraft gun ( SPAAG ) led to the ZSU - 23 - 4 Shilka . Description . The ZU - 23 - 2 ( 2A13 ) mounts two 2A14 23 mm autocannon s on a small trailer which can be converted into a stationary mount for firing the guns . While in this position the wheels are moved aside . The autocannon can be prepared for firing from the march position in 30 seconds and in emergency can be fired from the traveling position . The weapon is aimed and fired manually , with the help of the ZAP - 23 optical - mechanical sight which uses manually entered target data to provide limited automatic aiming . It also has a straight - tube telescope T - 3 for use against ground targets such as infantry as well as unarmored or lightly armoured vehicles . The ammo is a feed by a conveyor belt from two ammunition boxes . Each of the ammunition boxes are located on the side of the twin autocannon and each carries 50 rounds . The fumes created by firing the weapon are partially removed through the side openings in the barrels . Normally , once each barrel has fired 100 rounds it becomes too hot and is therefore replaced with a spare barrel . Each weapon is normally provided with two replacement barrels as part of its standard equipment . Tulamashzavod Joint Stock Company is offering to upgrade the 2A14 guns to the 2A14M standard with a barrel life of 10 , 000 rounds instead of 8 , 000 rounds . The cannon carriage is based on the earlier ZPU - 2 anti - aircraft twin heavy machine gun , which mounted two KPV 14 . 5 mm heavy machine gun s . ZU - 23 - 2 can be identified by different placement of the ammunition boxes ( at right angles to the gun carriage ) and by muzzle flash suppressors . In another similarity to the ZPU series , single - barrel and four - barrel versions of the ZU - 23 were also developed . However , these versions never entered service . ZU - 23 - 2 can be towed by a number of different vehicles . In USSR and later Russia the most frequently used towing vehicles for it were GAZ - 66 4x4 trucks and GAZ - 69 4x4 light trucks . Ammunition . The 23mm AA guns utilizes the same 23x152B case as the wartime VYa aircraft cannon . Due to different loadings and primers the ammunition is not interchangeable , however ; ammunition of the anti - aircraft cannon can be identified from its steel casings , ammunition for the aircraft cannon having brass cases instead . The following table lists the main characteristics of some of the available 23x152B ammunition used in 23mm AA guns : Not only the gun itself but also the ammunition is produced in several countries . In Bulgaria , the company ARCUS Co . produces rounds and fuses for the 2A7 and 2A14 guns . Service history . ZU - 23 - 2 entered service with the Soviet Army in 1960 . ZU - 23 - 2 is often mounted on trucks for use in both anti - aircraft and fire support roles . It can also be mounted on the roof of the MT - LB multi - purpose tracked APCs . Specially modified three - legged ZU - 23 - 2 is used in BTR - DG based airborne SPAAG . Cheap , easy to operate and still effective , the ZU - 23 - 2 is still used by the Russian Army and by more than 20 other armies . During Soviet invasion of Afghanistan , the Soviet forces put ZU - 23 - 2 sets to secure the air defense of occupation area ; also , the Afghan Mujahedeen utilized those ZU - 23 - 2 sets which were left behind by defeated or retreated Soviet forces , to fight back against Soviet air powers . In the later Afghan War , the belligerents including Taliban and Northern Alliance used ZU - 23 - 2 , along with SA - 7 or Stinger Missile , as their primary air - defense weapons . The type has seen widespread use by both sides in the Libyan civil war often mounted on technical pickup trucks . Notable appearances in media . The ZU - 23 - 2 appears in the video games " " , and " " as a towed weapon and also mounted on a variant of the BMD - 3 . The ZU - 23 - 2 also makes an appearance in " " as a weapon to fight an Mi - 24 Hind .