122 mm howitzer 2A18 ( D - 30 ) The 122 - mm howitzer D - 30 ( GRAU index 2A18 ) , is a Soviet howitzer that first entered service in the 1960s . It is a robust piece that focuses on the essential features of a towed field gun suitable for all conditions . The D - 30 has a maximum range of 15 . 4 kilometers , or over 21 km using RAP ammunition . With its striking three - leg mounting the D - 30 can be rapidly traversed through 360 degrees . Although no longer manufactured in FSU nations the D - 30 is still manufactured internationally and is in service in more than 60 countries ' armed forces . The barrel assembly of the 2A18 gun is used by the 2S1 self - propelled howitzer . There are also Egyptian , Chinese , and Syrian self - propelled variants and conversions . The Syrian conversion utilizes the hull of a T - 34 tank . History . The 122 mm ( originally 48 lines ) calibre was adopted by Russia in the early 20th century , becoming very important to Soviet artillery during the Second World War . Development of the D - 30 began in the 1950s , as a replacement for the M - 30 howitzer , widely used in divisional and regimental artilleries . The D - 30 also replaced remaining 76 mm M1942 guns in motor rifle regiments . Military requirements that led to the D - 30 can only be deduced . Its role supporting tank and motor rifle regiments , and Soviet doctrine from the Great Patriotic War , suggest that while indirect fire was the primary role , direct fire anti - tank was very important . The latter is evidenced by the very effective HEAT shell , the low silhouette of the piece , its wide and rapid top - traverse and its shield . The D - 30 was designed by the well established design bureau at Artillery Plant No 9 in Sverdlovsk ( now Motovilikha Plants in Yekaterinburg ) , at the time led by the eminent artillery designer Fëdor Fëdorovich Petrov ( 1902 - 1978 ) . This team was responsible for designing the earlier M - 30 , the post - war 152 mm D - 20 Gun - Howitzer , and other guns . Soviet divisional artillery was assigned to manoeuvre regiments ( in Regimental Artillery Groups - RAGs ) and as divisional troops ( in Divisional Artillery Groups - DAGs ) . A RAG was normally three batteries , each of six pieces , to each motor rifle and tank regiment . DAGs were mostly equipped with 152 mm pieces , but the DAG of a motor rifle division included a D - 30 battalion . The role of a RAG was a normal field artillery role to support manoeuvre forces with indirect , semi direct and direct fire . The D - 30 entered Soviet service in 1963 and is sometimes referred to as the M1963 . In 1967 widespread introduction of self - propelled guns was authorised and the D - 30 ’ s barrel and ammunition was used for the new 2S1 . When the 2S1 entered service it was usually assigned to tank regiments and motor rifle regiments equipped with BMP Infantry Fighting Vehicles ( IFVs ) . D - 30s were retained in motor rifle regiments equipped with BTR IFVs . The D - 30 has been widely exported and used in wars around the world , notably in the Middle East , and particularly in the Iran - Iraq War - a long - lasting war of attrition similar to World War I . The gun remains a mainstay of artillery forces in developing countries and is deployed in the War in Afghanistan . Soldiers from several western armies have been trained on the D - 30 by various user nations in order to be able to train Afghan soldiers on it . Description . Distinctive features of D - 30 include the low mobile mounting and the above - barrel recoil system . The three legged mobile mount is unusual for field artillery , with stabilisers that are clamped together for towing and then deployed when in action . Earlier similar designs were the 1939 French 47SA39 APX , and the German 1943 designs by Skoda and Krupp ; neither entered service . However , the Bofors 105 mm L28 Light Field Howitzer 4140 , was similarly arranged with four legs and did enter Swedish and Swiss service . The 1930s designed British 2 - pdr . anti - tank gun was another piece featuring a three - legged mounting . Also unusual is the large tow linkage fixed to the muzzle ; in transport the stabilizers are folded away and the barrel serves as a trail . Compared to the M - 30 , the new howitzer had a significantly longer 35 calibre gun barrel , just short of being a gun - howitzer by Soviet definition . Like other guns of the period it has a high efficiency muzzle brake ; this allowed an increased HE muzzle velocity of 175 m / s to 650 m / s , and raised maximum range by 3 , 500 m from 122 mm M - 30 and by 2000 m from 76 mm M1942 to 15 . 3 km . Weight increased by 650 kg over that of the M - 30 , to 3 , 150 kg ; the D - 30 was over twice the weight of the 76mm M1942 . Accuracy improved , with mean error at about 10 km dropping from 35 m with the M - 30 to just 21 m . Effective stabilisation length is a fundamental aspect of a gun mount , and legs 120° apart need to be longer than with a smaller angle . The D - 30 ' s design minimises this problem in several ways . Trunnions are close to the ground , as a result of placing the recoil system and cradle above the barrel . The trunnions are also at the very rear of the breech ; this maximises the recoil space when firing at higher elevation angles . Their rearward position also pushes the recoiling element forward on the mount , maximizing relative rearward span of the stabilizers and so stability during recoil . Additionally there is a very efficient muzzle brake , which absorbs about half the recoil . There is no mechanism to reduce recoil length as the angle of elevation increases . Some of the design decisions have a price . The muzzle brake produces about twice the overpressure in the area around the gun that is acceptable to western armies , and is the reason it is often seen being fired with a long lanyard , which reduces rate of fire . Furthermore , the maximum elevation angle is restricted to 18° ( early versions ) or 22° ( later versions ) when the breech is over a trail leg . This is enforced by a mechanical cam that prevents the piece firing for about 60 % of the total top traverse , and limits range to about 12 km , with full maximum range only possible in the central arc of about 48° between each pair of legs . The extreme rearward location of the trunnions means the elevating mass is unbalanced , requiring a strong balancing mechanism to enable manual elevation . To do this , the D - 30 uses compression balancing gears . A central jack is powered by hand operated hydraulics . This jack is lowered while the wheels are raised to permit two of the stabiliser legs to be swung 120° rearwards . The mounting is then lowered and the ends of the legs spiked to the ground . This mounting provides for quick traversing to fire in any direction . The pair of large tires are suspended on a single trailing arm ; maximum towing speed is 60 km / h on the road . As was normal in Soviet designs the tyres were filled with foam . Initially the D - 30 had no brakes and no seat for the layer - non - essential luxuries . A sliding block breech was adopted instead of M - 30 ’ s pre - 1914 screw pattern , permitting a slight increase in the rate of fire . This breech is semi - automatic vertical sliding block breech , with a tied jaw and the block moving down to open . It opens automatically and ejects the empty cartridge case when the gun fires . It is closely related to the design of the breeches on other Soviet post World War II guns and howitzers . The non - reciprocating sights are standard Soviet pattern , designed for one - man laying . Included are a direct fire anti - tank telescope , a panoramic periscopic indirect - fire sight ( a dial sight ) in a reciprocating mounting , an angle of sight scale , and a range drum for each charge engraved with the range ( distance ) scale . The elevation leveling bubble is mounted on the dial sight mount . The range drum enables the standard Soviet technique of semi - direct fire when the piece is laid visually on the target and the range set on the range drum . Soviet 122 mm howitzers used different ammunition to 122 mm guns , although there was some compatibility . In the case of ammunition for the D - 30 , the standard 122 mm howitzer shell weight of 21 . 8 kg was retained , with a metal cartridge case containing variable propelling charges . Cartridge and shell are loaded separately ; this means the shells have to be hand rammed by a man to the right of the breech with a ramming rod . The D - 30 could fire the older M - 30 ammunition , however new shells were also introduced , eventually including a rocket assisted projectile with a range of 21 . 9 km . The M - 30 ’ s range of propelling charges comprising base and 8 increments were replaced by a new set comprising base and four increments ; single base propellant was retained . A more effective High Explosive ( HE ) shell was developed , as well as smoke , illumination and chemical filled projectiles . In keeping with Soviet doctrine the anti - tank role is important ; there is a HEAT shell capable of penetrating 460 mm of steel armour plate . The maximum rate of fire of the D - 30 is 6 - 8 rounds per minute , and about 75 rounds per hour . There is disagreement as to whether this maximum rate of fire is achievable for indirect fire . Based on reloading speeds of similar guns using separate charges , solo re - laying , and given a stable emplacement , semi - automatic breech and no long lanyard , ( examples are the 25 - pdr . and 105mm L118 ) , and assuming concurrent lay adjustment during reloads , then it probably is when in the hands of a competent detachment . However , 5 - 6 rounds per minute may be more realistic with a poorly trained gun crew . The D - 30 is noted for simplicity of maintenance by its users ; reputedly there are no special tools , all jobs can be done with a wrench and large hammer . However , like any other gun routine maintenance is essential , and western troops in Afghanistan have reported Afghan manned D - 30s having problems with shells sticking in the barrel due to lack of cleaning . Self - Propelled Versions . MT - LB tracked vehicles were often employed by Soviet forces for towing instead of trucks . This led to the development of a self - propelled variant combining the gun with the chassis of the MT - LB , the 2S1 . This was the first Soviet enclosed turret self - propelled artillery gun , going into service in the early 1970s . The 2S1 is very light and mobile , and amphibious without preparation . Good mobility and quick reaction abilities of the 2S1 enhance the flexibility of the D - 30 , reducing its vulnerability in maneuver battles . Post 1973 , Syrian and Egyptian armed forces fielded D - 30 guns fitted to the hulls of obsolete T - 34 tanks , similar to Israeli conversions of Sherman hulls . This rather crude modification improves the speed of divisional artillery , allowing for the ability to match speed with front - line mechanized forces . A major drawback is the lack of protection for the gunners . Emplacement Procedure . A location chosen for emplacement of the D - 30 should be as level as reasonably possible . Firstly the carriage is raised via an internal hydraulic jack located under the cradle of the gun . Once the gun is at the required height the wheels are raised via the wheel lifting lever ; this allows the two split stabilizer legs to be separated from the mono stabiliser leg and brought rearward into firing configuration . The legs are then locked in place with locking pins . The carriage is lowered via the hydraulic jack so the legs touch the ground ; integral stakes are then hammered into the ground . At this point the gun is ready for direct fire using the OP4 direct fire sight , or can be orientated and have its position fixed via the aiming circles for subsequent indirect fire using the Pantel sight . Ammunition . The D - 30 fires separate loading projectile s , with variable charges :