76-mm Divisional Gun F-20 Technical Details
- Years of issue – 1934
- Total released – no data
- Caliber – 76 mm
- Weight in firing position – 1867 kg
- Barrel length – 3923 mm
- The length of the threaded part – 3292 mm
- Calculation – 6 people
- Travel speed – up to 30 km / h
- Rate of fire – up to 20 rds / min
- The greatest firing range – 14 300 m
- Direct shot range – up to 825 m
- Shooting angles:
- Horizontal – 60 °
- Vertical – 5 ° + 75 °
76-mm Divisional Gun F-20 Details
In the early 1930s, work was actively carried out in the USSR to create divisional universal (with circular fire) and semi-universal (intended for “defensive anti-aircraft fire”) guns.
Within the framework of the concept of a semi-universal (anti-aircraft divisional) gun (i.e., capable of simultaneously playing the role of an anti-tank, anti-aircraft and divisional gun) in 1933 in GKB-38 (design bureau of plant number 32 in the village of Podlipki near Moscow) was designed by the design team of V. G. Grabina new 76-mm divisional gun A-51. This gun was intended for limited combat against anti-aircraft targets (barrage), for fighting tanks and for solving all other tasks of a special divisional gun. Despite the fact that GKB-38 was liquidated in the same 1933, the project of the A-51 gun was still embodied in metal.
Design Bureau of the Novoe Sormovo plant No. 92 (Gorky), established in January 1934 under the leadership of V.G. Grabin (where the employees of the liquidated GKB-38 moved), continued to refine the project of the A-51 cannon. In 1934, the plant № 92 produced a prototype of the 76-mm semi-universal gun A-51, but already under its own factory index – “F-20”. The main requirement in its development was the preservation of the standard 76-mm cartridge case from the divisional gun of the 1902 model of the year. Therefore, the cartridge case for the ammunition of the new gun, while retaining its geometric dimensions, received an increased powder charge from 0.9 kg to 1.08 kg. The barrel of the new gun was also extended to 50 calibers, and the channel and chamber of its barrel were borrowed from the 76-mm anti-aircraft gun mod. 1915/1928, with which the F-20 cannon had similar ballistics.
The F-20 cannon consisted of a barrel with a semi-automatic vertical wedge gate and a sprung two-wheeled single-bar carriage with a pallet and large steel wheels.The originality of the design of this weapon was that the barrel was a free tube with a casing and a screw-on breech and a semi-automatic shutter. The shutter (vertical wedge) and semi-automatic control were almost entirely taken from the 76-mm anti-aircraft gun of the 1931 model of the year. A muzzle brake was mounted on the barrel – to partially absorb the recoil when fired.The gun had a hydraulic recoil brake, a hydropneumatic knurler, while the recoil length was variable. The spring balancing mechanism consisted of two cylinders. Lifting mechanism – sector. The sight and the vertical guidance mechanism were located on different sides of the barrel. The upper machine is a steel casting with a screwed-in forged combat pin. A shield was attached to the upper machine.
The wheels were used in two versions: with narrow rubber tires and with a metal rim. A crawler-type rotary mechanism (similar to the 32-K cannon) was attached to the trunk of the machine, with the help of which the gun was rotated. The pallet in the stowed position was hung out under the gun carriage; when it was switched to the firing position, the gun rolled onto the pallet. Firing in the normal position was carried out from the pallet, but it was possible to shoot from the wheels.The F-20 cannon had a projectile weighing 7.1 kg, with an initial speed of 710 m / s, and its maximum firing range reached 14300 m (with a vertical guidance angle of 45 °). The chamber was designed for a standard case mod. 1900, respectively, the gun could fire all the ammunition for the 76-mm divisional and regimental guns, and had the ballistics of the 76-mm anti-aircraft gun mod. 1915/1928. The gun ammunition included unitary shots: with caliber armor-piercing shells; high-explosive fragmentation shells, including high-explosive steel old Russian and French grenades; shrapnel; buckshot; incendiary and smoke shells. So, the armor penetration of a caliber armor-piercing projectile at an angle of 90 ° at a distance of 500 m for the F-20 gun was 75 mm, and at a distance of 1000 m – 67 mm.
At the beginning of 1935, the F-20 divisional gun was sent to field tests, which ended unsuccessfully. Since this gun had an outdated single-bar carriage design, its characteristics did not meet the requirements of the time and did not satisfy V.G. Grabin. In this regard, simultaneously with the work on its improvement, on the basis of the F-20 cannon, the design of a new divisional gun, which received the index “F-22”, was started, which was completed in 1935.
It was this weapon that became the first artillery system fully developed in the USSR (and not another modernization of the Russian army’s guns or foreign development), which was adopted by the Red Army in 1936.
The 76-mm divisional gun F-22, model 1936, had a modern design at the time of creation with sliding beds, with suspension and metal wheels with rubber tires. It was equipped with a semi-automatic vertical wedge gate, and a hydraulic recoil brake. The gun could fire all the ammunition for 76mm divisional and regimental guns. The maximum firing range is 14,000 m. For the first time, the F-22 cannon was successfully used in battles with Japanese troops on the Khalkhin-Gol River and near Lake Khasan. A total of 2,932 F-22 cannons were produced in 1937-1939. In 1939, they were replaced in production with more modernized 76-mm divisional guns designed by V.G. Grabin F-22USV model 1939.
On June 1, 1941, the Red Army units had 2868 F-22 cannons. During 1941 – 1942, these guns suffered heavy losses, but in small quantities they continued to be used in artillery units in the active army until the end of the Great Patriotic War.