120mm and 125mm Main Guns

2A46M LINE DRAWING

2A46M gun with T-80-style autoloader and gunner's instruments

125mm mainguns (D-81T and D-81TM; artillery department indices 2A26 and 2A46 respectively) equip all Soviet and Russian tanks starting with T-64A MBT. They were developed by the Spetstekhnika (OKB-9) design bureau in Ekaterinburg (former Sverdlovsk), and are manufactured at the artillery plants Plant No.9 in Ekaterinburg and Motovilikha in Perm.

One of the drawbacks of this gun is that a high strain on internal surfaces during firing, as well as sheer size of it demands strict manufacturing discipline which initially caused difficulties for the Soviet industry. This resulted in unsatisfatory fire consistency of original models due to all kinds of manufacturing defects, including substandard materials, poor machining, barrel drooping, and so on. It is worth noting, however, that this problem has received due attention during the upgrading efforts (2A46 mainguns), culminating in the purchase of the Western machining equipment for 2A46M/M-1. Improved manufacturing process and better stabilization and recoil equipment provided for increase in accuracy especially on the move and at medium to long ranges.

The average barrel life of production 2A26 guns, according to USSR standards, is 600 EFC. The barrel life of 2A46M guns is twice that (1200 EFC); this modernization also provided for a quick gun barrel replacement in field conditions.

Starting with T-64B, the gun has also been modified to allow it to be used as a launcher tube for ATGMs.

This main gun was developed from the early 60s and first introduced on a T-64A MBT, with the installation series of 20 vehicles delivered in 1967. The main reason for its introduction were the intelligence reports about a new British Chieftain MBT which couldn't be defeated frontally by 115mm D-68 gun originally installed on T-64.

With the upgoing gun and ammo design efforts this gun managed to stay quite abreast with the armor developments in the West until the introduction of M1A1HA model of the Abrams MBT, the reliable counter to which did not materialize due to a tremendous economic and political upheaval associated with the collapse of the USSR.

Currently the ammunition for 2A46M gun still corresponds to the level of threat that existed 15 years ago, and there are certain technical hurdles, primarily the autoloader dimensions, that prevent simple solutions to the problem.

Solutions do exist. These include a complex of deep modernization measures utilising an increased-power 125mm 2A82 gun, new ammunition with 740mm battle parts, and redesigned autoloader to accomodate those. There is also the project of radical increase in main gun caliber to 152mm (2A83?). Given the current geopolitical climate and Russian defence spending priorities, any efforts in this direction are unlikely to materialize in nearest years.

In the middle of the 90s the 125mm caliber gun 2A75 has been developed for a new light airborne tank 2S25 Sprut-SD. Designed to fire all types of 125mm ounds from a much lighter platform, this gun differs from D-81 line of guns in several important respects, including the more than doubled recoil length.

An interesting more recent development of high-caliber Russian mainguns are two 120mm guns M-393 and M-395, designed to fire NATO ammunition. These guns, intended for export only, are offered as an upgrade option for T-62 and T-72 tanks respectively.

Guns Specifications

Designation 2A26 2A26M2 2A46-1 2A46-2 2A46M 2A46M-1 2A46M-2 2A46M-4 2A46M-5 2A75 2A66 2A82
Internal designation D-81T D-81T D-81TM D-81K D-91T M-393 M-395
Year of introduction 1966 1969 1970 1976 01.04.1981 1981 1992 2005 2005 1995? 1989? dev. 2005?
Used on tanks T-64AT-72 T-64A
T-72A
T-64B
T-80B
T-72AV
T-72B
T-64BV T-72B
T-80BV T-80U
T-72S
T-90
T-80UM T-90A 2S25
Sprut-SD
O.187 T-62 T-72
Type Smoothbore
Caliber 125 mm 120 mm
Features
  Fume extractor +
  Thermal sleeve - +
  Chromium liner - +
  Quick-change barrel - +
Breechlock type Horizontal wedge, semiautomatic ?
Recoil devices 2, asymmetrical 2, symmetrical ?
Recoil resistance 98000 N ?
Recoil length 260..300mm, hard stop at 310mm 700mm ?700mm 310mm
Barrel length 6000mm ?5300mm 6000mm
Chamber length 383 mm ?
Gun length 6678mm ?
Barrel life 350 600 800 1200 ?
Gun mass 2500kg ?2600kg 2400kg
Pendulous elts. mass 2443kg ?
Recoiling elts. mass 1900kg ?
Barrel mass 1165kg ?
Max.chamber pressure 5100 bar 6500 bar ?
Ammunition two-part, separately loaded, with semicombustible propellant case unitary
Ammunition types APFSDS, HEAT, HEF, special rds ...+ATGM ...+high-energy APFSDS hi-pwr NATO ammo

 

2A46 GUNS AT MOTOVILIKHA PLANT

2A46 guns at Motovilikha plant


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