The Afanasev A-12.7 is a

heavy machine gun A heavy machine gun (HMG) is significantly larger than light, medium or general-purpose machine guns. HMGs are typically too heavy to be man-portable (carried by one person) and require mounting onto a weapons platform to be operably stable or ...

developed by Nikolay M. Afanasev in 1949 and adopted for service in 1953. This gun was supposed to have a considerably higher rate of fire than its predecessor, the

Berezin UB The Berezin UB (russian: УБ - Универсальный Березина) (''Berezin's Universal'') was a 12.7 mm caliber Soviet aircraft machine gun widely used during World War II. Development In 1937, Mikhail Yevgenyevich Berezin bega ...

aircraft machine gun. Due to excessive barrel wear however, it was eventually limited by an electrical trigger to a rate comparable to the Berezin UB. Initially intended to be mounted in the defensive turrets of the

Tu-4 The Tupolev Tu-4 (russian: Туполев Ту-4; NATO reporting name: Bull) is a piston-engined Soviet strategic bomber that served the Soviet Air Force from the late 1940s to mid-1960s. It was reverse-engineered from the American Boeing B-29 ...

bomber, the A-12.7 was ultimately installed only in trainer aircraft and helicopters. Nevertheless, it was produced for 30 years.

History

After the

Second World War World War II or the Second World War, often abbreviated as WWII or WW2, was a world war that lasted from 1939 to 1945. It involved the vast majority of the world's countries—including all of the great powers—forming two opposi ...

various attempts were made to increase the rate of fire of the Berezin machine gun. Reducing the cycle time by increasing the speed of the moving parts was the most obvious thing to do. However, this resulted in a considerable reduction of life and reliability. Another attempt was to reduce the motion length of the moving parts while retaining their speed within permissible limits. N. M. Afanasev took a different approach by introducing an

acceleration In mechanics, acceleration is the rate of change of the velocity of an object with respect to time. Accelerations are vector quantities (in that they have magnitude and direction). The orientation of an object's acceleration is given by t ...

lever A lever is a simple machine consisting of a beam or rigid rod pivoted at a fixed hinge, or '' fulcrum''. A lever is a rigid body capable of rotating on a point on itself. On the basis of the locations of fulcrum, load and effort, the lever is d ...

, which transferred the energy of a short motion actuating slide into a long motion of a

chamber Chamber or the chamber may refer to: In government and organizations * Chamber of commerce, an organization of business owners to promote commercial interests *Legislative chamber, in politics * Debate chamber, the space or room that houses delib ...

ing and case extraction arm. This way the motion length of the actuating slide could remain shorter than the overall length of the

cartridge Cartridge may refer to: Objects * Cartridge (firearms), a type of modern ammunition * ROM cartridge, a removable component in an electronic device * Cartridge (respirator), a type of filter used in respirators Other uses * Cartridge (surname), a ...

, thus increasing the rate of fire. Later, the same operating mechanism was used in the 23mm AM-23 and ZSU-23 cannon as well. Afanasev's prototype 12.7mm machine gun was designated TKB-481 and reached an impressive rate of fire of 1,400 rounds per minute. However, because of barrel wear problems a special electrical trigger system was introduced, that artificially reduced the rate of fire to 800 - 1,100 rounds per minute. With this modification the barrel life increased to 4,000 rounds, however the gun no longer had any distinct advantages over the Berezin UB. Nevertheless, in the autumn of 1953, Afanasev's 12.7mm aircraft machine gun was adopted put into production under the designation A-12.7. The

GRAU index The Main Missile and Artillery Directorate of the Ministry of Defense of the Russian Federation (), commonly referred to by its transliterated Russian acronym GRAU (), is a department of the Russian Ministry of Defense. It is subordinate to the ...

of the weapon is 9-A-016P. The A-12.7 machine gun is a gas-operated weapon with a vertically moving wedge breechblock. On the actuating slide two pivoting, jointed chambering levers are mounted. Those chambering levers actually work like the arms of a

praying mantis Mantises are an order (Mantodea) of insects that contains over 2,400 species in about 460 genera in 33 families. The largest family is the Mantidae ("mantids"). Mantises are distributed worldwide in temperate and tropical habitats. They ha ...

. The upper, longer lever is used to ram the cartridge from the belt link into the chamber. An extraction claw on its forward end is used to extract the fired cartridge case. The lower lever protrudes into the weapon housing and has a U-shaped recess on its lower end. As the actuating slide moves back and forth, a traverse lug in the weapon housing is cammed into this recess to guide the chambering levers. The A-12.7 aircraft machine gun has an electrical sear mechanism that is operated by a

voltage Voltage, also known as electric pressure, electric tension, or (electric) potential difference, is the difference in electric potential between two points. In a static electric field, it corresponds to the work needed per unit of charge to ...

of 26V. At the back plate a spring buffer is located. Ammunition may be fed from either the left or from the right side. A pneumatically operated charging mechanism on the left side of the receiver is used to charge the machine gun and to clear misfires. The cylindrical housing on the right side of the receiver contains the return spring of the actuating slide. The internal machining of the barrel of the A-12.7 was the same as the one of the

DShK The DShK 1938 ( Cyrillic: ДШК, for russian: Дегтярёва-Шпагина Крупнокалиберный, Degtyaryova-Shpagina Krupnokaliberny, links=no, "Degtyaryov-Shpagin large-calibre") is a Soviet heavy machine gun with a V-shaped bu ...

heavy machine gun, with 8 grooves 0.17 mm deep and 2.8 mm wide.Широкорад А.Б. (2001) ''История авиационного вооружения'' Харвест (Shirokorad A.B. (2001) ''Istorya aviatsionnogo vooruzhenia'' Harvest. ) (''History of aircraft armament''), page 120 Mi-4 gun

The A-12.7 machine gun never armed the Tu-4 bomber as initially intended. By then, machine guns were considered obsolescent for this purpose and 23mm cannon were employed instead. Therefore, the A-12.7 was only used in training

aircraft An aircraft is a vehicle that is able to fly by gaining support from the air. It counters the force of gravity by using either static lift or by using the dynamic lift of an airfoil, or in a few cases the downward thrust from jet engine ...

and

helicopter A helicopter is a type of rotorcraft in which lift and thrust are supplied by horizontally spinning rotors. This allows the helicopter to take off and land vertically, to hover, and to fly forward, backward and laterally. These attributes ...

s. The UTI trainer versions of the

MiG-15 The Mikoyan-Gurevich MiG-15 (russian: Микоя́н и Гуре́вич МиГ-15; USAF/DoD designation: Type 14; NATO reporting name: Fagot) is a jet fighter aircraft developed by Mikoyan-Gurevich for the Soviet Union. The MiG-15 was one of ...

MiG-17 The Mikoyan-Gurevich MiG-17 (russian: Микоян и Гуревич МиГ-17; NATO reporting name: Fresco) is a high-subsonic fighter aircraft produced in the Soviet Union from 1952 and was operated by air forces internationally. The MiG-17 w ...

and

MiG-19 The Mikoyan-Gurevich MiG-19 (russian: Микоян и Гуревич МиГ-19; NATO reporting name: Farmer) is a Soviet second generation, single-seat, twinjet fighter aircraft, the world's first mass-produced supersonic aircraft. It was the ...

aircraft carried a single A-12.7 machine gun. The main application of Afanasev's 12.7mm machine gun, however, was the armament of helicopters. The Mi-4A helicopter was equipped with a single gun with 200 rounds in the gondola below the

fuselage The fuselage (; from the French ''fuselé'' "spindle-shaped") is an aircraft's main body section. It holds crew, passengers, or cargo. In single-engine aircraft, it will usually contain an engine as well, although in some amphibious aircraf ...

. A single A-12.7 was also installed in the nose of the Mi-6A transport helicopter. The Mi-8TV had an A-12.7 machine gun in its nose as well and on the Mi-24A it was installed in the turret NUV-1. An exemplar can be seen at the :ru:Музей Войск ПВО and another at

Aviation Museum of Central Finland The Finnish Air Force Museum ( fi, Suomen Ilmavoimamuseo), formerly the Aviation Museum of Central Finland ( fi, Keski-Suomen ilmailumuseo), is an aviation museum located near Jyväskylä Airport in Tikkakoski, Jyväskylä, Finland. The museum ...

History

References

See also