The origins of this weapon go back to 1930 when the USSR bought a 7.62 cm (3") semi-automatic AA gun from the German company of Rheinmetall. It went into production for the Army as the 3-K gun. In 1932 the Navy asked for a design of a naval AA mount using this gun. The Bolshevik factory designed a naval mounting by simply placing the rotating part of the land gun on a new base. Unfortunately, this design proved to be unsuccessful and during the shipboard trials it proved impossible to elevate in rough seas.

In 1934 the Kalinin factory started a work on the new mounting design which was designated as 34-K. There were two versions of the gun, the first being a loose-liner design and second a conventional liner design, with the second one being adopted into service. It successfully passed both proving ground and shipboard trials in 1936 and went into production at the end of that year. Between 1936 and the end of 1941 285 of these guns and mountings were built. It was hand loaded and had no electrical powered systems. It is still being used by the North Koreans, but after 1942 in the USSR it was superseded by the 85 mm 90-K mount using the same mounting with an 85 mm barrel.

In 1936 design work started on a twin turret mount using the 34-K barrels. The trial mount was built in 1938 and was tested, but had many defects and was sent back for rework. The defects were fixed and mount went into production in October 1939. A total of 15 mount were built in 1940-41. This mount was designated 39-K and was basically a widened 34-K mount in an enclosed turret which was recessed about 1 meter (39.4 in) into the deck. The vertical and horizontal traverse mechanisms were electrically operated.

In 1939 work on a simplified twin mounting was started. It was supposed to be a simple shield mount that was easy to install and did not require special installation like the 39-K mount. This mounting received the designation of 81-K and the first four were finished by May 1940, with two more being completed later that year. These mounts were installed on the battleships Marat and Oktyabr'skaya Revolyutsia in 1941. However, these mountings did not enter production and no other ship received these weapons.

The gun has a monobloc tube design with a liner and screwed-on breech. Uses a vertical sliding breech block with inertial semi-automatics.

Gun Characteristics

Designation 76.2 mm/55 (3") 34-K Pattern 1935
Ship Class Used On 34-K
  Gangut class BBs, Krasnyi Kavkaz CL, Leningrad (Pr. 1) class DLs, Gnevny (Pr. 7) class DDs
  Soobrazitelny (Pr.7U) class DDs, some Novik class DDs, Marti minelayer
  Some Buryat and Vogul class river gunboats, some minelayers and auxiliary ships

  Tashkent DL, Ognevoy (Pr. 30) DD (1 finished, rest completed with different guns)
  Khasan (Pr. 1190) class river monitors, Kiev (Pr.48) class DLs (project)

  Marat, Oktyabr'skaya Revolutsia BBs

Date Of Design 34-K: 1935
39-K: 1939

81-K: 1940
Date In Service 34-K: 1936
39-K: 1940
81-K: 1941
Gun Weight 1.243 tons (1.263 mt)
Gun Length oa 166.26 in (4.223 m)
Bore Length 156.34 in (3.971 m)
Rifling Length 133.03 in (3.379 m)
Grooves 28
Lands N/A
Twist N/A
Chamber Volume 170.9 in3 (28 dm3)
Rate Of Fire 34-K: 15-18 rounds per minute
39-K: 12-20 rounds per minute


Type Fixed
Weight of Complete Round Distance Grenade (O-361D): 25.35 lbs. (11.5 kg)
FRAG (O-361K): 26.24 lbs. (11.9 kg)
Shrapnel (Sh-361): 25.35 lbs. (11.5 kg)
AP (BP-361): 25.35 lbs. (11.5 kg)
Projectile Types and Weights Distance Grenade (O-361D): 14.57 lbs. (6.61 kg)
FRAG (O-361K): 15.32 lbs. (6.95 kg)
Shrapnel (Sh-361): 14.57 lbs. (6.61 kg)
AP (BP-361): 14.33 lbs. (6.5 kg)
Bursting Charge Distance Grenade (O-361D): 0.401 lbs. (0.182 kg)
FRAG (O-361K): 1.065 lbs. (0.483 kg)
Shrapnel (Sh-361): 0.154 lbs. (0.07 kg)
AP (BP-361): none
Projectile Length Distance Grenade (O-361D): 5.04 calibers
FRAG (O-361K): 4.56 calibers
Shrapnel (Sh-361): 4.7 calibers
AP (BP-361): 3.67 calibers
Propellant Charge 4.01 lbs. (1.82 kg)
Cartridge: 6.09 lbs. (2.76 kg)
Muzzle Velocity Distance Grenade (O-361D): 2,658 fps (810 mps)
FRAG (O-361K): 2,628 fps (801 mps)
Shrapnel (Sh-361): 2,667 fps (813 mps)
AP (BP-361): 2,677 fps (816 mps)
Working Pressure 34-K, 39-K: 2500 kg/cm2
81-K: 2300 kg/cm2
Approximate Barrel Life 1,800 rounds until MV drops 5%
Ammunition stowage per gun Pr 7 and 7U DDs: 300 rounds


Range with 25.35 lbs. (11.5 kg) Distance Grenade (O-361D)
Elevation Distance
Max. Ballistic Range 9,810 yards (8,970 m)
Range with 26.24 lbs. (11.9 kg) FRAG (O-361K)
Elevation Distance
Max. Timer Range 16,010 yards (14,640 m)
Max. AA Ceiling 31,160 feet (9,500 m)
Effective AA Ceiling 21,325 feet (6,500 m)
Range with 25.35 lbs. (11.5 kg) AP (BP-361)
Elevation Distance
Max. Effective Range 4,375 yards (4,000 m)

Mount/Turret Data

Designation Single Open Mount: 34-K
Twin Turret Mount: 39-K
Twin Open Mount: 81-K
Weight 34-K: 4.872 tons (4.95 mt)
39-K: about 12.3 tons (12.5 mt)
81-K: about 11.81 tons (12 mt)
Elevation 34-K: -5 / +85 degrees
39-K: -5.5 / +87.5 degrees
81-K: -5 / +85 degrees
Rate of Elevation 34-K: 8 degrees per second
39-K: 11 degrees per second
81-K: 10 degrees per second
Train 360 degrees
Rate of Train 34-K: 12 degrees per second
39-K: 18 degrees per second
81-K: 18 degrees per second
Gun Recoil 15.35 - 18.7 in (39 - 47.5 cm)


"Naval Weapons of World War Two" by John Campbell
"The Naval Institute Guide to World Naval Weapon Systems 1991/92" by Norman Friedman
"Sovetskie Boevye Korabli 1941-45: IV Vooruzhnie" (Soviet Warships 1941-45: Volume IV Armament) by A.V. Platonov
"Entsiklopedia Otechestvennoi Artillerii" (Encyclopedia of Fatherland (Russian) Artillery) by A.V. Shirokorad
Special help from Vladimir Yakubov

Page History

21 November 2007 - Benchmark
17 December 2018 - Converted to HTML 5 format, minor changes