76-mm Mountain Gun GP (M-99) Technical Details
- Years of release – 1958 – no data
- Total released – no data
- Caliber – 76 mm
- Weight in firing position – 735 kg
- Barrel length – 1630 mm
- The length of the threaded part – 1122 mm
- Calculation – 6 people
- Travel speed – up to 60 km / h
- Rate of fire – sighting – 10 – 14 rds / min, maximum – 20 rds / min
- The greatest firing range – 10,000 m
- Direct shot range – 850 m
- Shooting angles:
- Horizontal – 45 °
- Vertical – 10 ° + 70 °
76-mm Mountain Gun GP M-99 Details
The 76-mm mountain gun GP (M-99) was developed in the post-war period and replaced the 76-mm mountain cannon of the 1938 model in service in the Soviet army, which proved itself well during the Great Patriotic War in combat in mountain conditions, as well as on rough and difficult terrain. The mountain cannon was designed in SKB-172 under the direction of M.Yu. Tsirulnikov in accordance with the decree of the Council of Ministers of the USSR of October 26, 1951. Soon, in 1953, a prototype of the gun, which received the index “M-99”, was manufactured at the plant
number 172 (Perm).
After a series of factory and field tests, the gun was refined at Plant No. 172 and on September 14, 1954, it was sent back for additional field tests. An experimental battery of mountain guns M-99 passed factory tests in December 1954 and, after making further improvements to the design of the gun, on April 21, 1955, they again enter military trials.
The M-99 cannon was officially adopted by the Soviet army in 1958 under the designation “76-mm GP mountain cannon”. At the same time, a new indexing of cannon artillery systems was introduced in the GRAU of the Ministry of Defense, and the M-99 gun received a new index “product 2A2”.
The gun has a collapsible barrel, which consists of a pipe, breech and casing. The breech and the pipe, connecting with each other with threaded sectors, fasten the casing. The internal structure of the barrel and ballistics are identical to the 76-mm mountain gun of the 1938 model. The shutter is horizontal wedge-type, with a semi-automatic spring type, independent of the roll speed (opening is performed by an opening spring, and closing – by a closing spring). The recoil devices are located in a cradle under the barrel. The recoil brake is hydraulic, spindle type, with a spring compressor. The reel is hydropneumatic. When fired, the recoil devices roll back together with the barrel. The lifting mechanism has one sector, the rotary mechanism is of the screw type.
The balancing mechanism is a spring, pulling type, mounted on the upper machine, where lifting and turning mechanisms are also assembled, providing a vertical angle of fire from -10 ° to + 70 ° and a horizontal angle of up to 45 °. The upper machine is connected to the lower machine with a pin. Sliding box-type beds, can be folded and disassembled into two parts. An auxiliary (front) roller of small diameter is fixed in the pivot on the front of the right frame for moving the weapon on the battlefield. An integral part of the upper machine is also a two-piece lightweight shield cover. It protects the crew from small arms bullets and fragments of artillery shells and small-caliber mines.
To reduce the weight of the gun, the shield cover can be removed. Single-pitched metal wheels from a Moskvich car with a gusmatic tire. Suspension – torsion type.
The gun is equipped with PGP or PGP-70 sights. The peculiarity of this gun is that it can conduct both flat and mounted shooting. To ensure high stability of the gun, at large elevation angles, the design of the lower carriage machine allows you to change the height of the line of fire from 650 mm – with an elevation angle of less than 30 ° to 850 mm – with an elevation angle of more than 30 °. The change in the height of the line of fire in the GP cannon is carried out by jointly turning the balancers of the lower machine and fixing them in two positions: with a low line of fire for shooting at elevation angles not exceeding 30 ° and with a high line of fire for shooting at elevation angles over 30 °.
In mountainous conditions, the cannon can be transported in the form of ten separate packs on pack animals. Moreover, the maximum weight of one pack does not exceed 85 kg. A trained crew of six people can disassemble the gun within 4 – 5 minutes. It takes about the same amount of time to assemble it. In the stowed position, the rear parts of the beds are folded up, thereby significantly reducing the length of the gun and facilitating its towing by a tractor along narrow and winding mountain roads.
The time for transferring from the traveling position to the combat position (without opening the ditches under the coulters) and vice versa is no more than 1 – 1.5 minutes. When used in the northern regions, the mountain gun can be equipped with a special LO-8 ski mount, which allows it to be transported through deep snow and swampy terrain. If necessary, you can shoot directly from the skis. The weight of the LO-8 ski mount does not exceed 85 kg. It is also possible to tow the gun by an all-wheel drive (4×4) vehicle. The presence of torsion suspension of the two-wheeled chassis ensures the movement of the gun with mechanical traction at a maximum speed of 60 km / h. The cannon, due to its small mass-dimensional characteristics, can also be transported by air – by military transport aircraft and helicopters.
Shooting from the GP cannon is carried out with separate-case loading shots with high-explosive fragmentation, armor-piercing, cumulative and smoke projectiles, as well as shrapnel. The maximum firing range of a high-explosive fragmentation projectile weighing 6.28 kg with an initial speed of 485 m / s is 10,000 m.
The 76-mm mountain gun GP was in service with the artillery units of the mountain rifle units of the Soviet army, was actively used in the hostilities of the Limited contingent of Soviet troops in Afghanistan in 1979-1989, as well as in numerous interethnic conflicts at the end of the 20th century in the territory of the former Soviet Union … Currently, the 76-mm mountain gun GP continues to be in service with the Russian army.