D-10 tank gun



The D-10 is a Soviet tank gun developed in late World War II, and installed in tank destroyers and tanks. Versions of the 100 mm gun were installed on new T-55 tanks as late as 1979, and continue to be in active service in many countries.

History
At the beginning of 1944, the T-34 tank's F-34 76.2 mm tank gun was replaced by a more powerful 85 mm gun. This rendered the year-old SU-85 tank destroyer effectively obsolescent, since its D-5T 85 mm gun was now also fielded by a more flexible medium tank. F. F. Petrov's Design Bureau at Artillery Factory No. 9 was assigned the task of producing a 100 mm antitank gun for the proposed SU-100. Petrov's team modified the S-34 naval gun for use in an armoured fighting vehicle.

The D-10 is a high-velocity gun of 100 mm bore diameter, with a barrel length of 53.5 calibres. Muzzle velocity of 895 m/s gave it good antitank performance by late-war standards. Initially it could penetrate about 146mm of steel armor plate angled by 30 degrees at 1,000 m range, superior to the German 75 mm KwK 42 mounted on the Panther tank and the original 88 mm guns such as the Tiger I's KwK 36, but not as good as the Tiger II's longer KwK 43 L/71 gun until after the war, when APDS and more modern ammunition types were developed. A more effective high-explosive shell was developed, taking advantage of the larger 100 mm bore.

It was originally designed to equip the SU-100 tank destroyer as the D-10S (for sаmokhodnaya, 'self-propelled'), and was later mounted on the post-war T-54 main battle tank as the D-10T (for tankovaya, 'tank' adj.). There was no significant difference in functionality or performance. It was also tested on the T-34-100, T-44-100, KV-100, and IS-2 (obyekt 245).

In 1955 a stabilizer (vertical-plane STP-1 Gorizont) and bore evacuator were added to the new D-10TG version of the gun. In 1956, the subsequent D-10T2S version of the gun began production for T-54B and T-55 tanks, equipped with two-plane Tsyklon gun stabilization.

Versions of the D-10 were installed on new tanks as late as 1979, and thousands still remain in service in various countries.

A version of the D-10 was installed as a coastal artillery piece in Finland in the 1960s. This weapon is designated 100 56 TK in Finnish Navy service and consists of a complete T-55 tank turret without the stabilizer but furnished with a manually operated ammunition lift, a shute for used cases, and gun laying apparatus allowing indirect fire directed by remote fire control. The maximum elevation of the barrel was also increased and the turret was furnished with new aiming optics, in some cases including a thermographic camera for night use.

Ammunition
The cartridge case is 695 mm long. During World War II, UOF-412 round carried the 15.6 kg (34.39 lbs) F-412 high-explosive fragmentation shell. Antitank ammunition available from World War II until the late 1960s was based on the UBR-412 round, including the BR-412 armour-piercing high-explosive projectile, with the ballistic-capped BR-412B and BR-412D ammunition becoming available in the late 1940s. There was also a D-412 smoke shell.

In 1964, the NII-24 research bureau started design work on an improved 3UBM6 antitank round. In 1967 the 3BM6 hyper-velocity armour-piercing discarding-sabot round (HVAPDS) entered service, which could penetrate 290 mm of armour at 2,000 m, or 80 mm of armour angled at 60 degrees from the vertical. It was later replaced by the 3BM8 HVAPDS projectile, with a tungsten carbide penetrator. High-explosive anti-tank (HEAT) rounds, which penetrate armour with the focussed explosion of a shaped charge, included the 3UBK4 with 3BK5M warhead, later replaced by the 3UBK9 with 3BK17M warhead.

In the 1980s, 3UBM11 antitank rounds were introduced, with 3BM25 armour-piercing fin-stabilized discarding-sabot (APFSDS) tungsten carbide penetrator, which increased its armor penetration.

In 1983, the T-55M and T-55AM tank upgrade program also added the ability to some tanks to fire the 9K116-1 Bastion guided missile system (NATO reporting name AT-10 Stabber), for long-range engagements of tanks and low-flying helicopters. The antitank missile is encased in the 3UBK10-1 shell, which is handled, loaded, and fired exactly like a conventional tank gun round. 1.5 seconds after firing, a laser guidance window in the tail of the round is uncovered, and its rocket engine ignites to burn for up to six seconds, with a total missile flight time of up to 41 seconds. The missile is very expensive, about half the price of a T-55M tank, but allows the venerable 100 mm gun to engage modern main battle tanks.

Missile ammunition includes:
 * 3UBK10-1 (9M117 Bastion), penetrating 600 mm at up to 4,000 m
 * 3UBK10M-1 (9M117M Kan) tandem warhead, penetrating 650 mm at up to 4,000 m
 * 3UBK23-1 (9M117M1 Arkan) extended-range tandem warhead, penetrating 750 mm at up to 6,000 m
 * 3UBK23M-1 (9M117M2 Boltok) extended-range warhead penetrating 850 mm at up to 6,000 m