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").
|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)|
|Chamber Volume||7.323 in3 (0.121 dm3)|
|Rate Of Fire||Cyclic: 200-260 rounds per minute|
|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)
|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|
|Max. Range||2,625 yards (2,400 m)|
|Effective AA Ceiling||6,560 feet (2,000 m)|
- "Entsiklopedia Otechestvennoi Artillerii" (Encyclopedia of Fatherland (Russian) Artillery) by A.V. Shirokorad
Special help from Vladimir Yakubov