25-mm Anti-Aircraft Cannon 72-K,The USSR

25-mm Anti-Aircraft Cannon 72-K Specifications

  • Years of issue – 1941 – 1945
  • In total, 4888 units were produced. (72-K); 237 dmg. (94-KM)
  • Caliber – 25 mm
  • Weight in firing position – 1210 kg (72-K); 2150 kg (94-KM)
  • Barrel length – 2095 mm
  • The length of the threaded part – 1683 mm
  • Calculation – 6 people
  • Travel speed – up to 60 km / h
  • Rate of fire – 240 rds / min (72-K); 480 rounds / min (94-KM)
  • The greatest firing range – 6000 m
  • Direct shot range – no data
  • Shooting angles:
  • Horizontal – 360 °
  • Vertical – 10 ° + 85 °

25-mm Anti-Aircraft Cannon 72-K Details

The experience of the First World War and the Civil War showed that the effect of firearms chambered for a rifle cartridge at altitudes up to 500 m was ineffective, and at high altitudes it was simply negligible. At altitudes above 2000 m, the only effective means of fighting aircraft could only be automatic cannons. In the 1930s, the leadership of the Red Army made the only correct conclusion that the ground forces and the navy needed automatic anti-aircraft guns with a high rate of fire to protect themselves from the air enemy.Initially, it was assumed that the armament of anti-aircraft divisions of rifle divisions would be anti-aircraft guns of caliber 37 – 45-mm and 76-mm, and air defense in the regimental link would provide complex (quadruple) 7.62-mm anti-aircraft machine gun mounts mounted in the bodies of trucks. However, the opinion soon prevailed that the air defense of the regiments should be replaced and a battery of small-caliber anti-aircraft guns of 25 mm caliber should be introduced into the staff of the regiments. At the beginning of 1939, in the design bureau of plant number 8 named. M. I. Kalinin (settlement Podlipki, Moscow region) under the leadership of M. N.Loginov began the development of a similar anti-aircraft small-caliber automatic cannon with an increased rate of fire for the regimental air defense. A group of plant specialists with the direct project manager L.A. The Loktevs managed to cope with this task in a fairly short time, and in the fall of 1939, a prototype of a 25-mm anti-aircraft gun was transferred to factory tests. When designing a new anti-aircraft gun, a number of design solutions were borrowed from the experience previously used in the creation of a 37-mm automatic anti-aircraft gun 61-K model 1939.

In March 1940, a new 25-mm gun was sent to the Research Anti-Aircraft Artillery Range for field tests. At the same time, the prototype, which previously had the factory designation “3IK-25”, received the standardized index “72-K”. Field tests of the 72-K gun lasted from April 15 to May 25, 1940. All the shortcomings, except one, were immediately corrected, and a more significant drawback – the strong vibration of the gun at a high rate of fire, interfering with the gunner, was subsequently eliminated in the factory.

Since the Red Army’s need for small-caliber anti-aircraft guns was extremely high, already in mid-1940, the 72-K gun was officially adopted under the name “25-mm automatic anti-aircraft gun of the 1940 model.”

The 25-mm 72-K anti-aircraft gun was a single-barreled small-caliber automatic gun on a four-carriage with an inseparable four-wheel drive. The anti-aircraft installation consisted of an automatic cannon (machine gun), an automatic anti-aircraft sight, a machine with aiming mechanisms, a balancing mechanism and a shield cover, and from a wagon. The assault rifle included a barrel with a bolt, automatic loading mechanisms (magazine and tray with a rammer), recoil devices and a cradle. All actions necessary for firing a shot (opening the bolt, cocking the striker, extracting the sleeve, feeding and discharging the cartridge, closing the bolt and releasing the striker) were carried out automatically by using the recoil force. The gun had a monoblock barrel with a screw breech.

To protect the gunners from blinding when firing and to soften the sharpness of the sound of the shot, a flame arrester was screwed onto the muzzle of the barrel. The barrel of the gun was easily replaceable in the field by the forces of calculation, its replacement was carried out in the case of strong heating during continuous firing, as well as in case of damage. The survivability of the gun barrel was 1200 – 1300 rounds. Vertical wedge shutter. The gun automatics worked on the principle of using the energy of the barrel recoil with a short recoil. The gun had a vertical wedge breech.To open the shutter manually during the first loading or reloading, there was a handle mounted on the cradle. The recoil brake is hydraulic – with a spring compensator. The rollback length is variable – from 118 to 136 mm. The recoil spring was assembled on the barrel. Automatic loading mechanisms consisted of a magazine and a tray with a rammer. Store food, from a clip with a capacity of 7 rounds, which were manually fed from above to the store by the loader.The store had a mechanism of mutual closure, with the help of which firing was automatically stopped in those cases when the loader did not have time to put another clip with cartridges into the store, and was resumed when the clip with cartridges was inserted without any reloading, and a new clip could be fed before the previous one was consumed, which provided the ability to conduct continuous fire, limited only by the skills of the loader and the intensity of heating the barrel. The device of the automatic trigger mechanism made it possible to conduct automatic and single fire. This provided a rate of fire up to 240 rds / min.

The vertical and horizontal guidance mechanisms were mounted on the machine on the right side. The elevation speed was 7 ° per revolution of the flywheel of the swing mechanism. The angle of vertical fire ranged from -10 ° to + 85 °. The horizontal angle of fire was unlimited. The fire control from the cannon was carried out using an automatic anti-aircraft sight or a K8-T collimator sight (for part of early-release guns).The sight provided the solution to the problems of meeting the projectile with the target, that is, the development of anticipated target coordinates according to the input data: slant range, speed, course and angle of dive or pitching of the target. The machine tool consisted of upper and lower parts. The upper part of the machine is rotating, providing horizontal guidance of the gun. At the same time, it was the basis for the swinging part of the gun. The lower part of the machine was attached to the carriage and served as the basis for the upper part. The imbalance of the swinging part was compensated by a special pull-type balancing mechanism.

To transport the gun, a four-wheeled cart with spring suspension for each wheel was used. Automotive-type wheels with rubber-filled tires. For the possibility of changing the direction of movement of the tool, the forward course is made pivot. In a combat position, the cart was not separated, but was used as a base. When transferring from the marching to the combat position, the gun was lowered onto four supports by turning the axes of the forward and reverse moves.The cruciform arrangement of the supports gave the gun the necessary stability during firing in any direction at all elevation angles. Smooth and easy lowering and raising of the cannon when it was transferred from the traveling position to the combat position and back was provided by special spring shock absorbers located inside the front and rear ends of the longitudinal girder of the vehicle.

To transfer the gun from the traveling position to the combat position, a trained gun crew took 40 – 45 seconds. The leveling of the cannon was carried out by jacks located at the ends of the longitudinal beam, as well as by folding side stops of the carriage. The cannons mounted in the bodies of the GAZ-AA and ZIS-5 trucks had especially high mobility.

In 1943, changes were made to the drawings and assembly technology, after which the 72-K anti-aircraft gun received an armored shield cover, which significantly increased its survivability in combat conditions when firing at ground targets . Unitary shots with incendiary fragmentation tracer, armor-piercing tracer and incendiary rounds were used for firing a 25-mm automatic anti-aircraft gun of the 1940 model. A fragmentation-incendiary tracer projectile, with self-destruction 10 seconds after the shot, was intended for firing at air targets. An armor-piercing tracer solid (without explosive charge) projectile was intended for firing at light tanks and armored vehicles. From a distance of 500 m at a target 2 m high at an angle of 90 °, it penetrated 34 mm armor, and at a distance of 1000 m – 26 mm armor, i.e. armor of all light tanks and armored vehicles of the enemy.

During the Great Patriotic War, the 25-mm 72-K automatic anti-aircraft gun was widely used by units of the Red Army’s air defense to combat enemy aircraft at ranges up to 2400 m and at altitudes up to 2000 m. If necessary, it was possible to fire from it at light tanks and armored vehicles. In the army air defense regiments, formed from June 1942, there were 12 guns of 37 mm or 25 mm (72-K) caliber, 12 large-caliber anti-aircraft machine guns and 8 quad anti-aircraft machine gun mounts. On May 1, 1945, the air defense forces of the Red Army had more than 4300 25-mm 72-K and 94-K anti-aircraft guns. The 25 mm 72-K anti-aircraft gun, despite its small caliber, became a real enemy for enemy aircraft.

The combat characteristics of the 25 mm 72-K anti-aircraft gun fully corresponded to its purpose. At 85-degree elevation, it could reach the enemy aircraft at the very zenith, and the maneuverability and lightning-fast adjustment of the sight made the enemy aircraft vulnerable not only in the dive, but also in the pitching mode. Anti-aircraft guns were often attached to anti-tank artillery. This was due to the fact that, due to the long barrel length, the anti-aircraft guns had a high initial velocity of the projectile, and, consequently, good armor penetration.In addition, the 1940 model 25-mm anti-aircraft guns were widely used to arm armored trains. On armored trains, 72-K guns were installed on special air defense armored platforms, 1 – 2 guns per armored platform, and there were variants of mixed weapons, when 37-mm 61-K or 12.7-mm large-caliber guns were installed on the air defense armored platform together with 72-K DShK machine guns.

At the end of 1943, a 25-mm twin automatic unit 94-K was designed on the basis of 72-K at the design bureau of plant No. 88 (Mytishchi). The gun was a combination of two 25mm 72-K anti-aircraft guns. The sight, horizontal guidance mechanisms, the machine and the wagon were borrowed from the 37-mm 61-K cannon, and the swivel mechanism from the 37-mm 70-K ship assault rifle. The installation had a shield cover. The transition time of the installation from the traveling position to the combat position was only 30 seconds. The calculation consisted of 9 people.

In 1944, 94-K passed field tests at the Donguz test site. After revision, the installation received the index “94-KM”. In the same year, it was adopted by the Red Army under the designation “25-mm anti-aircraft gun of the 1944 model.” In 1944, Plant No. 88 manufactured 12 94-KM units, and in 1945 another 225. The production of this unit was discontinued in 1945. Installation 94-KM had many design flaws, including unsatisfactory accuracy of the sight, smoke during firing and frequent failures of machine guns.The anti-aircraft gun was mounted both on standard carts of 25-mm anti-aircraft guns and on ZIS-11 trucks, which were an elongated ZIS-5 truck chassis. However, after the end of the war, in the same 1945, their production was discontinued due to some design flaws identified during operation. In particular, there were unsatisfactory accuracy of the sight, excessive smoke when firing and frequent failures of machine guns. Anti-aircraft guns 72-K and paired installations 94-KM based on them were successfully used against low-flying and diving targets, and were in service with the Soviet army for a long time after the end of the Great Patriotic War. Their replacement with more modern anti-aircraft guns ZU-23-3 began only in the first half of the 1960s.Along with this, the design of the 25-mm 72-K anti-aircraft gun turned out to be suitable for wide unification, and on its basis four anti-aircraft shipborne mounts were produced: 84-KM of the 1944 model, 2M-3, 2M-3M of the 1950 model, and the twin shipborne installation of a sample of 1954. If the land version 72-K was mounted on the chassis of the ZIS-5 and GAZ-AA vehicles, then the ship version was mounted on rotary armored towers.

The production of anti-aircraft guns was mastered in 1940 by plant No. 8, but in fact the serial production of the 72-K gun began only in 1941, and part of the 25-mm anti-aircraft guns, in the absence of carts, was mounted in the bodies of trucks. So, through December 1941, the Red Army received about 200 improvised 25-mm self-propelled anti-aircraft guns on the chassis of a GAZ-MM truck. However, in the fall of the same year, the production of 72-K guns was again discontinued due to the evacuation of this enterprise to the rear. The final release of 72-K guns was only possible by the end of 1941. Initially, 72-K cannons were produced by factories No. 172 and 4, and later, its production was mastered by factory No. 88
(Mytishchi, Moscow region), where a large-scale production of 72-K was established, and a number of changes were made to the design that improved the manufacturability of production. If in the second half of 1941 only 328 25-mm guns were produced, in 1942 – 228, then subsequently their production steadily increased and by 1944 reached a record figure of 2353 units. In total, during the years of production, from 1941 to 1945, 4888 72-K anti-aircraft guns and 237 coaxial 94-KM anti-aircraft guns were produced.

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