The design of this weapon was started in 1940 and was based upon the Army 72-K gun. Prototype testing in 1941 was unsuccessful and the gun was not accepted for production. It was then redesigned in 1943 and was accepted into production in 1944. In 1944-45 a total of 330 guns were built after which production was halted.

In 1944 a twin mount 3-1 was designed using two 84-KM guns. The trials were successful, but the mount was not accepted into production.

Guns used in single mountings are air-cooled and the mountings are similar to those used for 20 mm Oerlikon guns. These guns are clip-fed and single mountings have 11 ready clips.

Actual bore diameter is 25.4 mm (1.0").

Gun Characteristics

Designation 25 mm/76 (1") 84-KM
Ship Class Used On Light ships 1944-45
Date Of Design 1941-44
Date In Service 1944
Gun Weight 94.8 lbs. (43 kg)
Gun Length oa 82.52 in (2.096 m) (with flash suppresser)
Barrel Length 75.39 in (1.915 m)
Rifling Length 66.86 in (1.683 m)
Grooves 12
Lands N/A
Twist N/A
Chamber Volume 7.323 in3 (0.121 dm3)
Rate Of Fire Cyclic: 200-260 rounds per minute


Type Fixed
Weight of Complete Round FRAG incendiary tracer (OZR-132): 1.38 lbs. (0.627 kg)
AP tracer (Br-132): 1.51 lbs. (0.684 kg)
Projectile Types and Weights FRAG incendiary tracer (OZR-132): 0.635 lbs. (0.288 kg)
AP tracer (Br-132): 0.65 lbs. (0.295 kg)
Bursting Charge N/A
Projectile Length N/A
Propellant Charge 0.022 lbs (100 g)
Muzzle Velocity FRAG incendiary tracer (OZR-132): 2,980 fps (910 mps)
AP tracer (Br-132): 2,950 fps (900 mps)
Working Pressure 18.4 tons/in2 2,900 kg/cm2
Approximate Barrel Life 2,000 rounds
Ammunition stowage per gun N/A


Range with 0.635 lbs. (0.288 kg) and 0.65 lbs. (0.295 kg) shells
Elevation Distance
Max. Range 2,625 yards (2,400 m)
Effective AA Ceiling 6,560 feet (2,000 m)

Mount/Turret Data

Designation Single Mount 84-KM
Weight 1,885 lbs. (855 kg) (with ammunition and all support systems)
Elevation -9 / +85 degrees
Elevation Rate 7.3 degrees per second
Train 360 degrees
Train Rate 19.24 degrees per second
Gun recoil 4.65 - 5.43 in (118 - 138 mm)


Data from:

  • "Entsiklopedia Otechestvennoi Artillerii" (Encyclopedia of Fatherland (Russian) Artillery) by A.V. Shirokorad

Special help from Vladimir Yakubov