Yak-B 12.7

Unlike Western electric-driven Gatling systems, the Yak-B (GRAU index 9-A-624) utilizes a gas-operated self-driving system assisted by a spring-loaded firing device to initiate rotation. This configuration allows the weapon to reach its maximum rate of fire of approximately 4500 rounds per minute almost instantaneously, without the need for heavy or bulky external power sources.

The design features four rotating barrels connected to a central drum, fed by a belt system running along the left side of the turret. The weapon integrates a forced-air cooling system and requires rigorous maintenance due to accelerated wear on internal components caused by the violent acceleration of exhaust gases.

The weapon saw its baptism of fire during the Soviet intervention in Afghanistan, where it proved lethal against Mujahideen ambushes and supply convoys. Despite its effectiveness in suppressing enemy fire, critical issues emerged regarding chronic overheating and a tendency to jam after sustained bursts exceeding 250 rounds.

In addition to the conflicts in Chechnya and operations in Syria, the Yak-B was exported to numerous Warsaw Pact countries and Soviet-allied nations, equipping Mi-25 and Mi-35 export versions. In tropical or desert environments, dust and extreme temperatures often limited the reliability of the feeding system, requiring frequent field overhauls.

To mitigate reliability issues, the YakB-12.7M (9-A-631) variant was introduced, featuring reinforced mechanics and modified rifling pitches for increased service life. However, wartime experience convinced the Russian Air Force that the 12.7 mm caliber was insufficient against modern armored vehicles, leading to a transition toward higher-caliber autocannons.

In subsequent versions of the Mil helicopter, such as the Mi-24P and Mi-24VP, the Yak-B was replaced by the 30 mm GSh-30K twin-barrel cannon or the 23 mm GSh-23L. Although it remains in service with many air forces worldwide, the Yak-B represents the last major Russian heavy rotary machine gun before Russian attack doctrine definitively converged on the destructive power of autocannons.