Russia / USSR
57 mm/75 (2.24") AK-725 (ZIF-72)
Updated 19 November 2008
The problems with the 57 mm ZIF-31 and ZIF-71 mountings prompted the Navy in 1956 to issue a request for a completely new weapon system in this caliber.  The prototype was constructed in 1959 and by 1960 was going through proofing tests.  One of the problems noted during these tests was that the barrels had short lives, so new and improved barrels were designed which increased barrel life to over 750 rounds.  The mount was officially accepted into service in 1964 as the AK-725.

The AK-725 had twin water cooled ZIF-74 barrels, which were modified to use belt ammunition, thus allowing for longer firing periods before reloading.  Compared to the ZIF-71, this new weapon could fire bursts twice as long and had 80% less cooling time between bursts.  Each belt contains 550 rounds and the first round needs to be manually chambered.   The AK-725 was controlled by the ESP-72 fire control system, which was itself controlled by the MP-103 Bars radar.  In an emergency, the turret can be used manually via a simple optical gunsight.  This mount was in production from 1961 to 1988.

This weapon was not considered to be effective against anti-ship missiles, as was evidenced by a training accident in 1987 when a missile drone accidentally targeted the Small Missile Ship Musson. Musson was firing its AK-725 mount right up until the moment of impact, but was unable to hit the missile.  The ship was destroyed by the resulting fire, with 39 crewmen killed.

The barrel was of monobloc construction with vertical blade type breech.  Recoil operated with water-cooled barrels.  Both barrels were mounted on a common cradle.  The turret itself is unarmored but was hermetically sealed with 6 mm (0.24 in) thick aluminum sides.


Lithuanian Grisha class frigate with twin 57 mm on stern in June 1993
U.S. Navy Photograph No. DN-SC-94-00870


57 mm/75 AK-725 mount


Turya class patrol ship with an AK-725 mount on stern
Photograph from Jane's Warship Recognition Guide

Gun Characteristics
Designation 57 mm/75 (2.24") AK-725 (ZIF-72)
Ship Class Used On Moskva (Pr. 1123), Kresta I (Pr. 1134), Kresta II (Pr. 1134A), Nanuchka I (Pr. 1234), Poti (Pr. 204), Turya (Pr. 206M), Grisha (Pr. 1124), Ropucha (Pr. 775), Ivan Rogov (Pr. 1171) and Ugra (Pr. 1886) classes plus many others
Date Of Design 1958
Date In Service 1964
Gun Weight 610.68 lbs. (277 kg)
Gun Length oa 168.31 in (4.275 m)
Bore Length N/A
Rifling Length N/A
Grooves 16
Lands N/A
Twist N/A
Chamber Volume 92.15 in3 (1510 cm3)
Rate Of Fire 200 rounds per minute
Maximum burst length:  100 rounds per barrel
Type Fixed
Weight of Complete Round Russia / USSR
   Tracer-FRAG (UOP-281) - 14.0 lbs. (6.36 kg)
   Tracer-FRAG (UOP-281U) - 14.1 lbs. (6.40 kg)
   HE (UFB-71) - 14 lbs. (6.35 kg)

   Type 59 - HE-T:  16.3 lbs. (7.4 kg)
   Type 76 - HE-T:  16.8 lbs. (7.6 kg)

Projectile Types and Weights Russia / USSR
   Tracer-FRAG (UOP-281) - 6.17 lbs. (2.8 kg)
   Tracer-FRAG (UOP-281U) - 6.17 lbs. (2.8 kg)
   HE (UFB-71) - 6.17 lbs. (2.8 kg)

   Type 59 - HE-T:  N/A - probably about 6.17 lbs. (2.8 kg)
   Type 59 - AP-T:  N/A
   Type 76 - HE-T:  N/A

Bursting Charge Tracer-FRAG (UOP-281) - 0.37 lbs. (0.168 kg)
Tracer-FRAG (UOP-281U) - 0.34 lbs. (0.154 kg)


Projectile Length Tracer-FRAG (UOP-281U) - 3.9 calibers without the tracer

Type 59 - HE-T:  21.1 in (53.5 cm)
Type 59 - AP-T:  21.1 in (53.7 cm)
Type 76 - HE-T:  23.3 in (59.1 cm)

Complete Round Length Tracer FRAG (UOP-281) - (53.6 cm)
Tracer FRAG (UOP-281U) - (53.6 cm)
Cartridge Case Type, Size and Empty Weight Lacquered steel or drawn 70:30 brass, 57 x 348 mm SR, N/A
Propellant Charge 2.65 lbs. (1.2 kg)
Cartridge - 4.92 lbs. (2.32 kg)
Muzzle Velocity Russia / USSR:  3,346 fps (1,020 mps)

PRC Type 59:  3,346 fps (1,020 mps)
PRC Type 76:  3,280 fps (1,000 mps)

Working Pressure 44,090 psi (3,100 kg/cm2)
Approximate Barrel Life 750 rounds
Ammunition stowage per gun N/A
Note:  Uses the same ammunition as other Russian 57 mm guns except that the ammunition is supplied in 550 round belts.
Elevation With 6.17 lbs. (2.8 kg) Tracer-FRAG Shell
Max Ballistic Range 9,210 yards (8,420 m)
Max Timer Range 7,600 yards (6,950 m)
Mount / Turret Data
Designation Enclosed Twin AA Mount AK-725
Weight  14.27 tons (14.5 mt)
Elevation -10 / +85 degrees
Elevation Rate 30 degrees per second
Train -200 / +200 degrees
Train Rate 35 degrees per second
Gun recoil 11.81 -14.57 in (30 -37 cm)
Data from
"The Naval Institute Guide to World Naval Weapon Systems 1991/92" by Norman Friedman
"Jane's Ammunition Handbook:  Ninth Edition 2000-2001" edited by Terry J. Gander and Charles Q. Cutshaw
"Entsiklopedia Otechestvennoi Artillerii" (Encyclopedia of Fatherland [Russian] Artillery) by A.V. Shirokorad
Special help from Vladimir Yakubov