SBK machine gun
| SBK | |
|---|---|
 SBK machine gun on the FSR tripod | |
| Type | Heavy machine gun |
| Place of origin | Federation of Soviet Republics |
| Service history | |
| In service | 1972–present |
| Production history | |
| Designer | Y. A. Surikov and S. V. Belomestnykh |
| Designed | 1969 |
| Produced | 1971–present |
| Variants | SBKT |
| Specifications | |
| Weight | 25.4 kg (gun only) 41.2 kg (gun on tripod) 11 kg per 50-round belt |
| Length | 1610 mm |
| Cartridge | 12.7×108mm |
| Caliber | 12.7 mm |
| Action | Gas-operated |
| Rate of fire | 800 rounds/min |
| Muzzle velocity | 845 m/s (2,772 ft/s) |
| Effective firing range | 2,000 m vs. ground targets |
| Feed system | 50-round belt |
| Sights | Iron sights 4x magnifying optic (optional) |
The SBK machine gun (СБК Сурикова-Беломестныха Крупнокалиберный, SBK Surikova-Belomestnykha Krupnokaliberny, "SBK Surikov-Belomestnykh Heavy-Caliber") is a 12.7mm (.50-caliber) heavy machine gun developed in the Federation of Soviet Republics. It is named after the last initials of its two designers, Y. A. Surikov and S. V. Belomestnykh. It was adopted by the FSR's Army in 1972, and became standard on FSR tanks, such as the T-66 and T-74. It is also license-produced in Menghe, where it is designated GCh-75.
History
During the 1940s through 1960s, the Federation of Soviet Republics had produced the ShVK heavy machine gun in large numbers, and exported it to many of its allies. By the 1960s, however, the Army had begun to express interest in a replacement weapon, which would be lighter and more mobile while also offering a higher rate of fire.
A design team led by Y. A. Surikov and S. V. Belomestnykh responded with a prototype in 1969, drawing on a design they had initially proposed in the late 1950s. Their weapon was roughly ten kilograms lighter than the ShVK machine gun, and had a slightly higher rate of fire, while also offering modestly improved accuracy. The FSR's Army accepted the weapon for service in 1972, giving it the designation SBK after its designers.
An additional variant, designated SBKT, entered service in the same year. It is largely identical to the baseline SBK, but incorporates a different trigger system, and is incorporated into a crank-operated mount. The SBKT variant is used on cupola mounts for tanks and other armored vehicles.
Design
The SBK uses a gas-operated action, with a long-stroke piston. The rate of fire is 800 rounds per minute, making it more useful as an anti-helicopter weapon than the ShVK. Both left-fed and right-fed variants of the weapon are available.
The weapon is belt-fed from 50-round belts, which can be joined in 100-round or 200-round boxes. It fires the powerful 12.7×108mm cartridge, which can penetrate 25 millimeters of steel armor with its armor-piercing round. It can be fitted with a basket under the ejection port, which captures metal belt links for subsequent re-use and prevents spent casings from obstructing the commander's optics on tank mounts. This feature is most common on the SBKT but it has also been seen on regular SBK weapons.
In its infantry-mobile configuration, the SBK machine gun is usually mounted on a folding tripod developed alongside the weapon, allowing it to be fired from a crouching position. This mount also includes a hollow wooden stock and magnifying optic, and can be accurately aimed out to a range of 2,000 meters when engaging ground targets.
GCh-75
GCh-75 (Menghean: 75식 기관총 / 七五式機關銃, 75-sik gigwanchong) is the indigenous weapon designation applied to SBK machine guns license-produced in Menghe. The base weapons are almost exact copies of their FSR counterparts, differing mainly in the language and markings stamped on identifying components. As the name implies, the production license was granted in 1975, though large-scale production did not begin until 1979.
Other differences related to the configuration of the folding tripod mounts, which used straight legs on the Menghean version. The tripod-based GCh-75 was also aimed with iron sights and aimed and fired by means of a spade-handle grip rather than a conventional trigger assembly. This approach limited production costs, but also reduced the weapon's effective firing range.
GCh-75Ch
Like the SBK, the GCh-75 also came in a dedicated vehicle-mount version, designated JGCh-75Ch. This weapon is identical to the SBKT, though it also uses a different mount when connecting to the commander's cupola of a tank.
GCh-75G
The "G" variant (denoting 경 / 輕, Gyŏng, "light") is an upgraded version of the GCh-75 first produced in 1995. It makes use of lighter components, shaving about a kilogram off of the overall weight. The greatest reduction in weight, however, comes from the use of a bipod mount, eliminating the need for a separate 16-kilogram tripod. The GCh-75G is also easily recognized by a large muzzle brake and a stock and optics configuration similar to that used on the original tripod SBK, which together improve the weapon's accuracy at long ranges.
The GCh-75G is most commonly seen with special forces and airborne and mountaineer units, where its lighter weight, greater accuracy, and bipod mount make it preferable to the heavier tripod versions still common in the Army's regular ground units.
Service
The SBK machine gun and its license-produced relatives have been produced in large numbers by the Federation of Socialist Republics and its current and former allies, and have been exported around the world. It has earned a reputation as a rugged and reliable weapon,
Soon after it was accepted into service, the SBKT was installed on the "A" variant of the FSR's T-66 tank, which until then had lacked a separate machine-gun for the commander. It is also used by all variants of the FSR's T-74, including the T-91 main battle tank that succeeded it.
In Menghe, the GCh-75 has been produced in similarly large numbers, both for infantry-mobile and vehicle use. It is the commander's weapon on the MinChŏl-5 and SuChŏl-6 main battle tanks, as well as on the MinChŏl-4 and the BSCh-5D IFV. It is also the main armament of the BSCh-7 APC.
Users
Menghe- {{country data Federation of Soviet Republics|flag/core|name=Federation of Soviet Republics|variant=|size=}}