Designed to engage tanks, moving and stationary armored ground targets by direct and indirect fire.

It is capable of all-round fire. The Sprut-B is a smoothbore towed gun provided with a power propulsion unit.

A high rate of aimed fire (6 to 8 rounds per minute) is ensured by the reliably functioning machinery and convenient arrangement of elevating and traversing controls.

Wide and rapid fire maneuver is provided by the carriage with three split trails allowing high laying angles in elevation and traverse. Worm-type mechanisms are used to elevate and traverse the barrel.

To reduce the effect of various weather conditions, the barrel mounts a special heat protection jacket.

The Sprut-B gun is equipped with various sighting devices to deliver accurate fire. For direct fire, use is made of the OP4M-48A optical sight in daytime and the 1PN53-1 night sight at night.

The gun is also provided with the 2Ts33 iron sight which is used jointly with the PG-1M panorama telescope for indirect fire or in the event of optical sight failure.

The gun can be towed by the Ural-4320 truck or MT-LBu multipurpose tracked prime mover.

The 125mm Sprut-B smoothbore antitank gun is simple in design, easy to operate and reliable to function.

The 125 mm 2A45M (Sprut-B) auxiliary-propelled towed anti-tank gun is also known as the Sprut-B (Russian for Octopus) and was developed as the potential replacement for the 100 mm MT-12/T-12 towed anti-tank gun which entered service in 1955.

The weapon was developed in the late 1980s by the F F Petrov design bureau at the Artillery Plant No 9 at Yekaterinburg, which also designed the famous 122 mm D-30 artillery system and numerous tank guns.

According to Russian sources, the development of the 2A45M (Sprut-B) towed anti-tank gun can be traced back to 1967, when it became apparent that existing in-service smoothbore 100 mm T-12 MT-12 series towed ant-tank gun (covered in detail in a separate entry) could not defeat new generation tanks such as the UK's Chieftain and the MBT-70 (which in the end did not enter service).

In January 1968 OKB-9, which subsequently became part of the now Joint Stock Company Spetstehnika, was selected to develop a new 125 mm anti-tank gun. It had the same ballistics as the 125 mm D-81 smoothbore tank which subsequently became the standard Russian tank gun.

The 125 mm smoothbore gun is installed in many MBTs including the Russian T-64, T-72, T-80 and T-90 as well as in the T-84 MBT developed in Ukraine.

Originally two versions of the 125 mm anti-tank gun were developed to the prototype stage, the D-13 towed and the SD-13 self-propelled. Further development of the latter resulted in the 2A45M (Sprut-B). This remains at the prototype stage.

The 125 mm system is based on the well-known 122 mm D-30 towed howitzer carriage which has been in service with RFAS and many other countries for well over 40 years.

The 122 mm rifled ordnance of the D-30 has been replaced by a modified version of the 125 mm D-81 smoothbore ordnance used in the T-64/T-72/T-80/T-84/T-90 MBTs and features a thermal sleeve and a large single 'T'-type baffle muzzle brake with a towing eye mounted underneath like the earlier D-30. Ballistically, the 125 mm 2A45M and the 125 mm tank guns are identical. The cradle is also taken from the 125 mm D-81 tank gun.

The barrel of the 2A45M consists of a tube with a muzzle brake attached by a casing to the chamber part and a breech ring. The breech mechanism is of the semi-automatic mechanical vertical sliding wedge type. This is opened manually before the first round is loaded and after that opens automatically after the weapon has fired.

The recoil system is a counteracting piston-type hydraulic buffer with the counter recoil system being pneumatic, with both mounted above the ordnance.

The 2A45M towed anti-tank gun has a mechanised system to convert from the firing position to the travelling position and this consists of a hydraulic jack and hydraulic cylinders. With the aid of the jack the carriage is raised to the required height for folding or unfolding the trails, then lowered onto the ground. The hydraulic cylinders raise the gun to the maximum clearance and also raise and lower the wheels.

When deployed in the firing position, the weapon rests on three trails that are normally staked to the ground to provide a more stable firing platform.

The system takes between 90 and 120 seconds to come into action and between 120 and 160 seconds to come out.

The system can be brought into action manually or using hydraulic assistance with the Auxiliary Propulsion Unit (APU) running.

The design of the carriage is such that the upper part of the weapon can be quickly traversed through a full 360° to be laid onto new targets.

A well-sloped shield provides the crew with limited protection from small arms fire and shell splinters. The 2A45M is fitted with an auxiliary propulsion unit consisting of an MeMZ-967A four-stroke petrol engine with hydraulic drive which allows it to propel itself around the battlefield at a maximum speed of 10/14 km/h. The engine is mounted on the right side with power transmitted to the road wheels via cardan shafts. The driver's seat is mounted on the left side and is provided with the necessary controls for controlling the system when the APU is being used.

The 2A45M is normally towed by a 6 × 6 truck that also carries the crew and ammunition to as near the firing position as possible. A small wheel attached to one of the three trail legs is then lowered and the 2A45M moves under its own power to the firing position.

The driver is seated in front of the shield on the left side and steers using a conventional steering wheel which folds forward when not required.

The two large rubber-tyred road wheels of the carriage are powered and claimed to be bulletproof with steering accomplished by altering the power to either road wheel.

The 2A45M weighs 6,575 kg when deployed in the firing system compared to the standard 122 mm D-30 towed howitzer which weighs 3,210 kg.

The sights, elevation and traverse equipment are positioned on the left side. Optical systems fitted include the OP4M-48A direct fire day telescope and the 1PN53-1 night sight. The iron sight 2Ts33 is used together with the panoramic sight PG-1M for indirect firing.

The 125 mm 2A45M fires the same family of separate-loading ammunition (projectile and semi-combustible cartridge case) as the T-64/T-72/T-80/T-84/T-90 MBTs and maximum rate of fire is quoted as 6 to 8 rds/min. A total of six ready rounds (projectile and charge) can be carried on the system for ready use with the remainder being carried in the towing vehicle.

The APFSDS-T projectile is used to engage MBTs and has an effective range of 2,100 m while the HE-FRAG projectile is used to engage general battlefield targets such as personnel. It contains 3.4 kg of A-IX-2 explosive and is fitted with a V-429E impact fuze.

Maximum range in the indirect fire role is 12,200 m compared to the 15,400 m (without using a rocket-assisted projectile) of the 122 mm D-30, as the latter has a maximum elevation of +70°.

The HEAT projectile has a V15 nose-mounted base activated fuze and contains 1.76 kg of A-IX-1 or OCFOL explosive which will penetrate the conventional passive first-generation MBTs such as the M60, M48 and Leopard 1 unless they are fitted with explosive reactive armour.

he 125 mm 2A54M anti-tank gun system can fire the 125 mm laser-guided projectiles fired by the latest RFAS MBTs, the 9K120 Refleks or Sniper. Both these projectiles have a range of 5,000 m and a single HEAT warhead, which will penetrate 700 mm of conventional steel armour. More recent versions have a tandem HEAT warhead to defeat explosive reactive armour (ERA).

In order to fire these 125 mm laser-guided projectiles a 9S53 laser fire-control system has to be used. This would be integrated onto the weapon.

This is based on the carriage of a 125 mm 2A45M (Sprut) towed anti-tank gun and is covered in a separate entry.