YakB-12.7 mm machine gun

The Yakushev-Borzov YakB-12.7 mm is a remotely controlled 12.7×108mm caliber four-barrel rotary cannon developed by the Soviet Union in 1973 for the Mil Mi-24 attack gunship and low-capacity troop transporter, with 1470 rounds, which can also be mounted in GUV-8700 machine-gun pods with 750 rounds. It has a high rate of fire (4–5,000 rounds per minute) and is also one of the few self-powered guns of the Gatling type (i.e. it is gas-operated, rather than requiring an external motor to operate).
On the Mi-24 it is mounted in the VSPU-24 undernose turret, with an azimuth of 60° to either side, an elevation of 20°, and a depression of 60°. The gun is slaved to the KPS-53AV undernose sighting system with a reflector sight in the front cockpit.
It was replaced by the fixed, side-mounted GSh-30K or the swivel-mounted GSh-23L in the late mark of the Mi-24 helicopters, as it did not provide enough firepower against dug-in or lightly armored targets that did not necessitate a rocket attack but it is still used on Mil Mi-24, Mil Mi-36, and Mil Mi-40 helicopters.