D - 10 tank gun The D - 10 is a Soviet tank gun developed in late World War II , and installed in tank destroyer s and tank s . 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 :