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 Rate of fire is the frequency at which a specific weapon can fire or launch its projectiles. This can be influenced by several factors, including operator training level, mechanical limitations, ammunition availability, and weapon condition. In m ...

than its predecessor, the

Berezin UB The Berezin UB () (''Berezin's Universal'') was a 12.7 mm caliber Soviet aircraft machine gun widely used during World War II. Development In 1937, began designing a new large-caliber aircraft machine gun chambered to the 12.7 mm roun ...

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 (; NATO reporting name: Bull) is a piston-engined Soviet strategic bomber that served the Soviet Air Force from the late 1940s to the mid-1960s. The aircraft was a copy of the American Boeing B-29 Superfortress, having been reve ...

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 (1 September 1939 – 2 September 1945) was a World war, global conflict between two coalitions: the Allies of World War II, Allies and the Axis powers. World War II by country, Nearly all of the wo ...

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 (mathematics), rate of change of the velocity of an object with respect to time. Acceleration is one of several components of kinematics, the study of motion. Accelerations are Euclidean vector, vector ...

lever A lever is a simple machine consisting of a beam (structure), beam or rigid rod pivoted at a fixed hinge, or '':wikt:fulcrum, fulcrum''. A lever is a rigid body capable of rotating on a point on itself. On the basis of the locations of fulcrum, l ...

, which transferred the energy of a short motion actuating slide into a long motion of a chambering and case extraction arm. This way the motion length of the actuating slide could remain shorter than the overall length of the cartridge, thus increasing the rate of fire. Later, the same operating mechanism was used in the 23mm AM-23 and

ZSU-23 The ZSU-23-4 "Shilka" is a lightly armored Soviet self-propelled, radar-guided anti-aircraft weapon system (SPAAG). It was superseded by the 2K22 Tunguska (SA-19 Grison). Etymology The acronym "ZSU" stands for ''Zenitnaya Samokhodnaya Ustanovk ...

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 acronym GRAU (), is a department of the Russian Ministry of Defense. It is subordinate to the Chief of ...

of the weapon is 9-A-016P. The A-12.7 machine gun is a

gas-operated Gas-operation is a system of operation used to provide energy to operate locked breech, Semi-automatic firearm, autoloading firearms. In gas-operation, a portion of high-pressure gas from the Cartridge (firearms), cartridge being fired is used t ...

weapon with a vertically moving wedge

breechblock A breechblock (or breech block) is the part of the firearm action that closes the breech of a breech loading weapon (whether small arms or artillery) before or at the moment of firing. It seals the breech and contains the pressure generated by ...

. 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 ...

. 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-shape Many shapes have metaphorical names, i.e., their names are metaphors: these shapes are named after a most common object that has it. For example, "U-shape" is a shape that resembles the letter U, a bell-shaped curve has the shape of the vertical ...

d 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 (electrical) potential difference, electric pressure, or electric tension, is the difference in electric potential between two points. In a Electrostatics, static electric field, it corresponds to the Work (electrical), ...

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 that of the

DShK The DShK M1938 (Cyrillic: ДШК, for ) is a Soviet heavy machine gun. The weapon may be vehicle mounted or used on a tripod or wheeled carriage as a heavy infantry machine gun. The DShK's name is derived from its original designer, Vasily Degtya ...

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 ( aircraft) is a vehicle that is able to flight, fly by gaining support from the Atmosphere of Earth, air. It counters the force of gravity by using either Buoyancy, static lift or the Lift (force), dynamic lift of an airfoil, or, i ...

and

helicopter A helicopter is a type of rotorcraft in which Lift (force), lift and thrust are supplied by horizontally spinning Helicopter rotor, rotors. This allows the helicopter to VTOL, take off and land vertically, to hover (helicopter), hover, and ...

s. The UTI trainer versions of the

MiG-15 The Mikoyan-Gurevich MiG-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 the first successful jet fighters to incorporate s ...

MiG-17 The Mikoyan-Gurevich MiG-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 was license-built in China as the Shenyang J-5 an ...

and

MiG-19 The Mikoyan-Gurevich MiG-19 (; NATO reporting name: Farmer) is a Soviet second generation, single-seat, twinjet fighter aircraft. It was the first Soviet production aircraft capable of supersonic speeds in level flight. A comparable U.S. " Cen ...

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 language, French ''fuselé'' "spindle-shaped") is an aircraft's main body section. It holds Aircrew, crew, passengers, or cargo. In single-engine aircraft, it will usually contain an Aircraft engine, engine as wel ...

. 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 (), formerly the Aviation Museum of Central Finland (), is an aviation museum located near Jyväskylä Airport in Tikkakoski, Jyväskylä, Finland. The museum exhibits the aviation history of Finland, from the early ...

History

References

See also