KPV heavy machine gun The KPV - 14 . 5 heavy machine gun ( KPV is an initialism for Krupnokaliberniy Pulemyot Vladimirova , in Russian as Крупнокалиберный Пулемёт Владимирова , or КПВ ) is a Soviet designed 14 . 5×114mm - caliber heavy machine gun , which first entered service as an infantry weapon ( designated " PKP " ) in 1949 . In the 1960s the infantry version was taken out of production because it was too big and heavy . It was later redesigned for anti - aircraft use , because it showed excellent results as an AA gun , with a range of 3 , 000 meters horizontally and 2 , 000 meters vertically against low flying planes . It was used in the ZPU series of anti - aircraft guns . Its size and power also made it a useful light anti - armour weapon on the BTR series of vehicles and the BRDM - 2 scout car . KPVT . The version for use in armoured vehicles is called the " KPVT " ( " tankoviy " , ' tank ' ) . KPVT is used for armoured vehicle installations , boats , movable and stationary mounts and various antiaircraft mounts . It features a shorter receiver and a heavier barrel jacket . The KPVT also uses a 50 - round belt instead of the original 40 - round belt . KPVTs are the primary armament of the wheeled BTR - 60PB / 70 / 80 series armoured personnel carriers and BRDM - 2 armoured reconnaissance vehicles . It is intended for fighting against light armoured targets , weapons systems and light shelters at the distances of up to 3000 m , as well as air targets at distances up to 2000 m . Naval armament . The naval version was called the marine tumbovaya ( MTPU ) . It was mounted in the following turrets ; 2M - 5 was for torpedo boats , the 2M - 6 for patrol boats , and the 2M - 7 for trawlers . In 1964 , amongst other small craft combatants , the North Vietnamese Navy had 12 P4 Motor Torpedo Boats in their inventory . On 2 August 1964 , three P4s belonging to NVN Torpedo Boat Squadron 135 attacked the US destroyer USS " Maddox " in the Tonkin Gulf . The " Maddox " fired over 280 5 inch ( 127mm ) shells at the charging boats , thus preventing them from discharging their 550 lb TNT armed torpedoes within the necessary 1 , 000 yard effective range . All six torpedoes missed . However , as the torpedo boats were moving at nearly , they commenced to duel the destroyer with their 14 . 5mm heavy machineguns , scoring only one hit on the US warship in the process . At the time of the " Tonkin Gulf Incident " , US identification manuals described the P4 as being equipped with 25mm guns , thus identifying the spent projectile ( as well as in after action reports ) as 25mm instead of the actual 14 . 5mm caliber bullet . As the duel between the destroyer and torpedo boats ended , and each departed in opposite directions , 4 F8 Crusader s from the aircraft carrier USS " Ticonderoga " attacked the retreating boats . The Crusaders fired Zuni rockets and 20mm cannons , while the 3 boats replied with their 14 . 5mm machineguns . The jets reported leaving one boat in sinking condition ( it limped back to base ) , and one F8 was heavily damaged , which was reported as shot down by the NVN , but in fact also limped back to its carrier . The 14 . 5mm marine pedestal machine gun mount ( 14 . 5mm MTPU ) is intended for combat against armoured surface , coast and air targets . It is mounted on decks of boats and can defeat surface and coast targets with a range of 3 , 000 meters horizontally and 2 , 000 meters vertically against low flying planes . Mechanics . The development of the machine gun began in 1944 . The 14 . 5×114mm M41 cartridge can be used with High Explosive Incendiary - Tracer ( HEI - T ) or Armour - Piercing Incendiary ( API ) bullets , and they have approximately twice the energy of a 12 . 7 mm ( . 50 BMG ) projectile . The KPV is air - cooled and fitted with barrel with a hard chrome plated bore . It uses a short recoil operation system with gas assistance and a rotary bolt . It can be fed with the 40 - round metallic belt from either the left or right side . The barrel can be removed by turning the prominent latch on the forward end of the receiver and pulling on the barrel ' s carrying handle . Versions . The ZPU is a towed anti - aircraft gun based on the KPV . It entered service with the Soviet Union in 1949 and is used by over 50 countries worldwide . Quadruple - ( ZPU - 4 ) Double - ( ZPU - 2 ) and single - barreled ( ZPU - 1 ) versions of the weapon exist . Ammunition . Rounds are also produced by Bulgaria , China , Egypt , Poland , and Romania .