The Mechanised Infantry Assault Gun – An Analysis

By Rexer

This guest article written by Rexer provides a fascinating historical account of the assault gun, tracing its pre-20th Century origins to the development of current day systems. Building on previous discussions of this topic, the article makes a case for adding this capability to UK Strike Brigades. Rexer is a serving British Army officer with significant experience and an encyclopaedic knowledge of military vehicles and weapons.

(Main image: US M-18 Hellcat assault gun / tank destroyer from WW2. This mounted the larger 76 mm gun used in later Sherman tanks. Designed from the outset as a tank destroyer, it was light, compact and extremely agile. It was highly regarded among those who used it and considered to be an extremely successful design. )


01. Introduction
02. Historical background
03. Modern Assault Gun Development
04. Conclusions

01. Introduction

Changing technology might modify the details of warfare, but many of the more general principles remain unaltered; and it may be found that the answers to the problems of today and tomorrow lie, at least in part, in the solutions of yesterday[1].

Assault guns have been identified as one of the potential enhancements to Mechanised Infantry (Mech Inf) capability that would mitigate the threat from heavier Armoured Fighting Vehicles (AFV) and enemy positions with Anti-Tank Guided Weapons (ATGW). There is strong historical precedence for this capability, which could inform the Concept of Employment (CONEMP) and Innovation, Research and Experimentation (IRE) activity and develop requirements. The aim of this note is to highlight existing Historical and Operational Analysis (OA) that supports the requirement for an Assault Gun to inform further activities.

02. Historical background

The requirement for mobile, direct fire (DF) support is not new. Such capabilities can be traced back to the Roman cohortes equitatae (‘mixed cohorts’) of the 1st Century AD. These were combined arms units of infantry and light cavalry supported by mounted archers and carroballista (‘cart-mounted bolt-throwers’), which were designed for garrison and ‘frontier policing’ operations but could also hold their own in regular warfare. This trend re-appeared during the 17th and 18th centuries in the form of Legions consisting of “one or more battalions of light infantry – jager or chasseurs a pied – a battery of highly mobile light artillery, several squadrons of light cavalry – including dragoons – a company of support troops: engineers, sappers, various craftsmen, linguists (for infiltrating enemy population centres, interrogating prisoners, etc) and medical staff[2].

Mobile fire support was a key element of the legions, particularly those in Continental Europe, which used ‘infantry guns’ (as opposed to ‘horse artillery’), such as the lightweight ‘leather guns’ used by Gustavus Adolphus of Sweden during the Polish-Swedish War (1626-29). The use of similar weapons during the English Civil Wars (1642-51) led to the introduction of Regimental Guns to the British Army, when James II issued each infantry battalion with two bronze 3-Pounder Grasshoppers in the 1690s. These continued in British service until the 18th Century, when each battalion had two Regimental Guns, crewed by an Officer and 34 Other Ranks. These were used extensively in North America during the War of Austrian Succession (1740-48), the Seven Years’ War (1756-63) and the American Revolution (1765-83)[3].

Infantry guns fell out of favour during the French Revolutionary (1792-1802) and Napoleonic (1803-15) wars, when the Royal Horse Artillery (RHA) was created to provide mobile fire support. However, some guns continued to provide direct support to the infantry, such as the 3-Pounder guns carried on mules during Wellington’s pursuit of the French across the Pyrenees in 1813 and when, during the Spanish Carlist Wars (1835-39), the British Auxiliary Legion formed two batteries equipped with small howitzers and Congreve rockets carried by mules. An officer of the Bengal Artillery who served with the Legion took this concept back to the East India Company’s Bombay Presidency Army, which formed several ‘mountain trains’ equipped with light guns carried by mules, camels and even elephants. Following the Indian Mutiny (1857), the Indian artillery batteries were disbanded except for five Mountain Batteries, which were absorbed by the Royal Artillery.

In 1899, the Royal Artillery was split into the Royal Field Artillery (RFA) and the Royal Garrison Artillery (RGA), which manned fortress, coastal and siege artillery. The RFA was, therefore, responsible for providing infantry support (the cavalry being supported by the RHA), but the RGA also absorbed the Mountain Artillery batteries, which provided RGA personnel with opportunities for active service overseas. The batteries were equipped with 2.5-inch ‘Jointed’ Rifled Muzzle-Loading (RML) guns, which split in half for ease of transport and were used extensively by the Indian Army (and other Colonial forces) during the Second Afghan War (1878-80) and Great Uprising (1897) on the North-West Frontier. The utility and effectiveness of these Mountain guns was immortalised in Rudyard Kipling’s poem “Screw Guns” (1890), including the verse:

Just send in your Chief an’ surrender – it’s worse if you fights or you runs: You may hide in the caves, they’ll only be your graves, but you can’t get away from the guns[4].

The ‘Screw Guns’ were still in service during the Second South African War (1899-1901) but their black powder charges made them easy targets for long-range marksmen and they were over-matched by the Boers’ modern breech-loading artillery. As a result, RGA and other Mountain batteries were equipped with new 10-Pounder ‘Jointed’ Breech-Loading (BL) Mountain guns in 1901. The Argyll and Ross batteries of the IV (Highland) Mountain Brigade (Territorial Force) had Mountain guns carried by Highland ponies instead of mules; landing at Gallipoli with the 7thIndian Mountain Brigade in 1915. More 10-Pounder Mountain guns were also used in East Africa by the 22nd (Derajat) and 24th (Hazara) Mountain batteries of the Frontier Force and Number 10 Section RFA was formed in November 1917 to support Lawrence of Arabia; equipped with 10-Pounder Mountain guns carried en portée by Talbot trucks.

A further modification of the 10-Pounder, known as the 2.75-inch BL Mountain Gun, was adopted in 1911 and over 180 guns were produced during the Great War (plus 290,000 shells). An Indian Mountain Battery equipped with these guns was sent to France in November 1917, but proved unsuited to conditions on the Western Front and was transferred to Egypt, whereupon it accompanied the British Salonika Force to Macedonia. An ‘off the shelf’ Vickers 2.95-inch Quick Fire (QF) Pack Howitzer had also been adopted by the Anglo-Egyptian Army and the West African Frontier Force in 1901. The same design was adopted by the US Army as the 75mm Pack Howitzer or Millimetre Gunand used during the Philippine Insurrection (1899-1901)[5]. These experiences demonstrated that Mountain guns, particularly when carried en portée, were well-suited to expeditionary warfare and influenced the development of future infantry support weapons.

The British 10-Pounder 2.75″ BL Mountain Gun. Adopted for infantry close support, it was used by Lawrence of Arabia in 1917 and mounted in a Talbot truck.

The German Army, like other European nations, had used infantry guns during the 19th Century but adopted a series of minenwerfer (‘mine throwers’) or mortars, developed by Rheinmetall, immediately prior to the Great War. The 7.58cm leichtes Minenwerfer (leMW) was issued as an ‘infantry gun’ in 1916, including the leMW neuer Art (nA) or ‘new model’ with a longer barrel and turn-table allowing them to be used as DF and Anti-Tank (ATk) weapons. However, the lack of dedicated infantry guns forced the German Army to use captured Belgian 5.7cm Maxim-Nordenfelt and Russian 76.2mm Putilov Model 1910 ‘fortress guns’ instead[6]. Based on these improvised weapons, Krupp produced a cut-down version of the 7.7cm Feldkanone 1896 nA as the 7.7cm Infanteriegeschutz, but the German Army decided to order Austro-Hungarian Skoda 7.5cm Model 1915 Gebirgskanonen to use as both Mountain and Infantry guns; although only small numbers were obtained before the end of the war.


The Germans also used the 57mm Maxim-Nordenfelt to arm their A7V tanks, which reflected the use of similar 6-Pounder (57mm) Hotchkiss QF naval deck guns and 75mm ‘Blockhaus Schneider fortress gun-mortars on British and French tanks respectively. However, it is less well-known that the use of armoured ‘gun cars’ with heavy DF weapons pre-dates the tank. Typical examples include the Pierce-Arrow and Seabrook ‘armoured lorries’ (armed with VickersQF 3-Pounder guns to support the lighter Rolls-Royce and Lanchester armoured cars of the Royal Naval Division’s Armoured Car squadrons in 1914-16), Renault 47mm Autocanon (manned by French Fusiliers Marins in 1915-16) and the British-designed Putilov-Garford ‘heavy gun cars’, armed with a 76.2mm Putilov Model 1910 gun, used by the Imperial Russian Army on the Eastern Front and, subsequently, by ‘Red’, ‘White’, ‘Green’ (ie. Nationalist Estonian, Latvian and Polish) and German Freikorps units during the Russian Civil War (1919-21) and various post-war conflicts. These represent the ‘First Generation’ of wheeled fire support platforms, which would now be designated as an Assault Gun, Fire Support Vehicle (FSV) or Mobile Gun System (MGS).

British and French doctrine also influenced the development of fire support for the US Army. By 1918, US Infantry Regiments (equivalent to British brigades) included a Machine-Gun (MG) Company, a Mortar Platoon (with 3-inch Stokes mortars) and a Gun Platoon equipped with French Canon d’Infanterie de 37mm Modele 1916 Tir Rapide Puteaux (TRP); all of these being motorised. The ‘Puteaux Rapid Fire’ was typical of the various ‘trench guns’ developed to destroy MG nests and pillboxes on the Western Front, but were also employed as the first ATk weapons, mounted on early tanks, such as the French Renault FT-17 (also used by the Italian, Polish, Russian/Soviet, Spanish and US armies), and on aircraft. The 37mm TRP remained in French, Polish and US Army service until 1940 and was the basis for the Japanese 37mm Tashio 11 (M1922) infantry gun[7].

Although weapon development was severely restricted by the Treaty of Versailles, Rheinmetall began development of the7.5mm leichtes Infanterie Geschutz 18 (leIG 18) in the 1920s, including a variant for use as a Gebirgsgeschutz(leGebIG 18), which were to be used until 1945. However, the German Army issued a requirement for a heavier weapon, which Rheinmetall produced in 1933 as the 15cm schweres Infanterie Geschutz 33 (sIG 33). Early variants were towed by horses and were still in the majority even when war had broken out, so they struggled to keep up with mechanised forces during the invasion of Poland (1939). As a result, many units created improvised SP mounts for the15cm sIG 33, which led to the development of so-called Sturmpanzers (‘assault tanks’) using obsolete and captured light tank chassis from late 1939[8].

Despite some experimentation with ‘trench guns’, the British Army had continued to use Mountain guns and Pack howitzers to provide infantry support after the Great War[9]. A new 3.7-inch QF Pack Howitzer entered service in 1917 and saw limited operational use in East Africa and Mesopotamia (70 guns had been produced by 1918, of which 28 saw action). It saw more-extensive use during the British Army’s Inter-War campaigns as, although the RGA re-merged with the RFA in 1926, each Infantry Division was provided with a Light Artillery Brigade equipped with 3.7-inch QF Pack Howitzers until 1936. A Light Battery, carried en portée by trucks, was also attached to the Experimental Mechanised Force and the 3.7-inch Pack Howitzer replaced the 13-Pounder QF Field guns of the RHA, towed by Vickers ‘Light Dragon’ artillery tractors, small numbers remaining in service throughout the war for specialist roles[10].

The 3.7-inch QF Pack Howitzer also replaced the Royal Navy’s 12-Pounders as ‘landing guns’ to support the Royal Marines ashore and was not declared obsolete until 1960. A modified version, fitted with the breech of the Vickers 3-Pounder (47mm) tank gun, was fitted to Vickers ‘Medium’ Infantry Close Support (ICS) tanks from 1923 to 1939.  Subsequently, two Cruiser ICS tanks with 3-Pounder guns were issued to each Royal Tank Regiment (RTR) Battalion and Company HQ until 1940 (the unit and sub-unit designations reflecting the RTR’s infantry support role), as well as Daimler Mark I (ICS) armoured cars. A similar 3-inch (76mm) howitzer was fitted to Matilda and Valentine (ICS) tanks and the air-portable Tetrarch (ICS) light tank, together with a modified version of the T17E1 Staghound Mark II (ICS) armoured car used by the New Zealand Division Cavalry (Armoured Car) Regiment in 1943[11].

Perhaps the British Army’s best ‘ICS gun’ was the 75mm Royal Ordnance QF (ROQF) gun, which was a 6-Pounder re-chambered to fire 75x350mmR ammunition from the US M2 (L/31) and M3 (L/40) guns used on the M3 Grant/Leeand M4 Sherman medium tanks. The gun was identical to the standard 6-Pounder, meaning it could be used on any vehicle designed for that gun, but delivered a more effective 6.76kg HE shell at velocities of 2,050 feet per second – judged to be superior to the 6-Pounder; the US 3-inch M3; and even the heavy 17-Pounder in the ICS role. As the 75mm M2/M3 was also a tank gun, it could fire an Armour-Piercing (AP) shell able to penetrate 81mm (3.2 inches) of armour at 500m[12]. The ROQF gun was fitted to Churchill and Cromwell ICS tanks as well as the AEC Mark III (ICS) and T17E1 Staghound Mark III (ICS) armoured cars[13].

Whilst the British ICS guns were used as ‘accompanying artillery’ (despite the British Army not using this European term), they also had secondary ATk roles, although some, such as the 3.7-inch QF Pack Howitzer, were less ideal as they lacked armour-piercing ammunition[14]. By 1936, therefore, all of the ‘Pack batteries’ had been converted into standard Field Artillery units, except for two RHA Light Brigades to support the new Mobile Divisions. However, the requirement for ATk capabilities remained and, in 1938, several of the former Light Brigades were re-converted into Infantry ATk Regiments[15]. ATk Companies were formed at brigade-level in 1938 but replaced by ATk Platoons (with portée guns) in each Infantry Battalion due to manpower shortages[16].

Early experience with the British Expeditionary Force (BEF) in France and the ‘Desert Rats’ in North Africa led to the employment of light guns carried en portée to provide mobility[17]. Although not originally designed to be fired from the truck, this became common practise and led to the development of the Self-Propelled (SP) 6-Pounder Deacon, based on a protected AEC Matador truck. The Deacon was reasonably effective against Italian tanks in North Africa but was an interim solution and scheduled to be replaced by a 6-Pounder mounted on a US M3 halftrack, produced under the US Lend-Lease scheme as the 57mm T-48 Gun Motor Carriage (GMC)[18]. However, by the time the new vehicle had been developed, the 6-Pounder was ineffective as an ATk gun and the T-48 GMCs were sent to Russia as Lend-Lease. However, heavy armoured cars and wheeled SP ATk guns such as the British Deacon, French LafflyW15 TCC and US GMC halftracks represent the ‘Second Generation’ of the wheeled Assault Gun, FSV and MGS.

Deacon ICS gun 6-pounder
During WW2, the British Army’s 6-Pounder anti-tank gun mounted on an AEC Matador truck to provide a primitive infantry close support gun and proved adept at neutralising enemy vehicles in North Africa until heavier armoured Axis tanks appeared.

This reflected the British Army’s view of the infantry support role but infantry fire support was viewed differently by the German Wehrmacht, who employed Infantry Guns throughout the Great War. Inter-war analysis concluded that the Sturmtruppen would have been able to seize their objectives more quickly and with fewer casualties if they had fire support from mobile armoured platforms. Whilst this support could have been provided by support tanks in the German Panzer formations (like the British ICS concept), the diversion of tanks for infantry support was considered a waste of valuable resources. This resulted in the creation of Sturmartillerie (‘Assault Artillery’) to support mechanised forces and saw the development of the archetypal Assault Gun; the Panzerkampfwagen (PzKpfw) III Sturmgeschutz(StuG III).

The StuG III holds a seminal place in the history of the German Panzer and wider the history of Armoured Fighting Vehicles (AFV) as it was one of the few designs to serve throughout the war; largely in its original form. The design had its origins in a requirement drafted by General Erich von Manstein (regarded as ‘father of the Sturmartillerie’) in 1935, which recommended that each infantry division be supported by its own Assault Gun Battalion with three 6-gun batteries.  By 1937, an experimental Assault Gun Battery had been created to develop and trial new designs, but none of the STuG batteries were available for the invasion of France and the Low Countries in 1940. As a result, the Army had to improvise using the 15cm sIG ‘Sturmpanzers’ covered previously, but also used a variety of even less formal designs mounted on captured trucks and wheeled armoured vehicles.

German Sturmgeschütz IIIG is perhaps the most iconic of all assault gun designs and is frequently referred to whenever the need for a modern version of the same type of weapon is articulated. Inexpensive versus standard Panzer II and IV tanks, it was still a highly effective infantry close support weapon. This vehicle type destroyed more allied AFVs than any other German tracked vehicle of the period.

Operational experience with the Sturmpanzers provided several lessons, which were incorporated in subsequent development of the StuG III, including increased armour protection and the replacement of the original 7.5cm L24 Sturmgeshutz Kanone Model 1937 (StuK 37) with the 7.5cm L43 StuK 40 (and, subsequently, the L48 StuK 40) gun based on the Panzer Abwehr Kanone Model 1940 (PaK 40). In 1942, a variant of the StuG III was fitted with a modified 10.5cm leichte Feldhaubitze Model 18 (leFH 18) to create the SdKfz 142/2 Sturmhaubitze Model 1942 (StuH 42), which was designed to enhance ICS capabilities, whilst the standard StuG III was increasingly used in the ATk role. With this development came a re-organisation of the Assault Guns into Sturmartillerie brigades comprising a Brigade HQ, three Assault Gun batteries and a Grenadier Battery to act as infantry escorts.

Although Assault Guns were never an organic part of German infantry divisions as Manheim had intended, their adaptability and ability to integrate powerful weapon systems saw them employed increasingly as Panzerjager (‘tank hunters). Guderian, as Inspector-General of Armoured Troops, stated that: “Anti-tank defence will devolve more and more on the assault guns, since all our other (infantry) anti-tank weapons are becoming increasingly ineffective against new enemy equipment… All divisions on the main battle fronts, therefore, need to be supplied with a certain complement of these weapons…[19] A summary of Tactics, Techniques and Procedures (TTP), taken from the Wehrmacht Assault Gun Commander’s Handbook, can be found at Annex A.

As traditional ATk weapons were over-matched by the new Soviet T-34 and KV-1 tanks, the Sturmartillerie became one of the Wehrmacht’s most potent ATk capabilities; destroying over 13,000 enemy tanks by December 1943 and no less than 30,000 by the end of the war.  Over 10,500 Assault Guns were built and Guderian’s prediction that ATk roles would become increasingly important for the Assault Gun saw the design become the basis for dedicated Panzerjager; over 6,000 of which were built by 1945.

Similarly, the US Army had no new infantry support weapons in service by 1940, having to rely on the venerable French 75mm Model 1897 Gun, even though the Westervelt Board had made comprehensive recommendations regarding future requirements in 1919. Some consideration was given to a new weapon in the mid-1930s when a 25mm Hotchkiss gun was purchased for evaluation, but there were insufficient funds to bring anything into service. It was observations from the Spanish Civil War (1936-39) that finally prompted the US Army to purchase a German 37mm PaK 36, which they adopted as the 37mm M3 ATk Gun in December 1938.

Nevertheless, the defeat of the French and BEF in Europe created a crisis for the US Army.  At this time, like many European nations, their tactical doctrine favoured the traditional thin cordon of guns to defend against attack, but lessons from the Battle of France suggested that this approach was inadequate against massed Panzer attack. However, the only new guns to have entered US service since the Great War were the 75mm Pack Howitzer (1927), the 105mm M1 Field Howitzer (1928) and the new 37mm M3 ATk gun (1938) and were not available in sufficient numbers[20]. As an emergency measure, the US Artillery Department created a ‘new’ ATk weapon using surplus 75mm M1897 guns, which were issued to one ATk Battery per Artillery Battalion[21].

In 1941, the US Army also developed a new Infantry Gun, finally replacing the old French 37mm TRP. To simplify design and production, the gun was based on a cut-down 105mm M2 Howitzer mounted on a 75mm M1A1 Pack Howitzer carriage. It also fired the same 105mm ammunition as the M2 Howitzer, although its light weight meant that could only use the first seven charge bags, which limited the maximum range to 7,250 yards (compared to 12,205 yards). The gun was adopted as the 105mm M3 Infantry Gun and issued to a new Cannon Company in each US Infantry Regiment in 1942. However, the guns were regarded as an unwelcome burden by the infantry and re-designated as the 105mm M3 Pack Howitzer, which served alongside the 75mm M1A1 Pack Howitzer with the newly-created US Airborne forces until the end of the war.

The US Army’s T30 Howitzer Motor Carriage mounted a 75 mm Pack Howitzer was an early attempt to provide infantry units with a robust assault gun.

At the same time, new doctrine was issued instructing the infantry to place a minimal number of guns forward, but to retain most as a mobile reserve. In practise, this was difficult to achieve as each US Infantry Regiment still only had one ATk Company and one Cannon Company with enough guns to allocate just one 4-gun platoon of each per Infantry Battalion. In mitigation, the US Army Chief of Staff, General George C Marshall, directed his staff to devise a more effective structure in April 1941. The Infantry Cannon companies were disbanded and Artillery ATk batteries were incorporated into new ATk battalions on 24 July 1941; separate ATk battalions were also organised under the control of General Headquarters (GHQ). The towed 37mm M3 ATk guns were issued to the infantry, but more mobile capabilities were created by mounting 37mm M3 and 75mm M1897 guns on vehicles; creating the 75mm M3; 75mm M5; and 37mm M6 Fargo GMCs[22].


In addition to the new SP ATk guns, in 1942, the US Army also mounted 75mm M1A1 Pack and 105mm M2 Field howitzers on M3 halftracks; designated the 75mm T30 HMC and 105mm T19 HMC respectively. These were issued to a Cannon Company in each US Armoured Regiment, as well as the Regimental Reconnaissance Platoon and the HQ of each Tank Battalion; providing a US equivalent of the British ICS tanks. A total of 312 T30 and 324 T19 HMCs were produced, seeing service in North Africa, Sicily and Italy. However, these interim designs were replaced by the 75mm M8 Scott and 105mm M7 Priest HMCs in 1943[23].

These designs reflected reports of British ‘portée guns’ and the French 47mm Laffly W15 TCC successfully engaging German Panzer formations during the Battle for France; although these reports failed to note that such successes were few and far between and that such guns were too few in number to have any significant impact. However, the performance of the GMCs during the Louisiana War Games (1941) was judged to have been an improvement over towed guns as they provided the only mobile forces to support the infantry. As a result of these lessons, General Marshall ordered the formation of more Armoured regiments and a new ‘anti-armour corps’; resulting in the existing ATk battalions being re-named Tank Destroyer (TD) battalions, which subsequently formed the TD Force (TDF) on 3 December 1941.

Initially, TD battalions were allocated eight M3 GMC, six M5 GMC and four M6 Fargo GMCs, but the latter platforms were withdrawn and each battalion received 36 M3 GMCs instead[24]. Around 2,200 M3 GMCs were produced and served with TD battalions in the Philippines, North Africa and Sicily until 1943. They were also used by the US Marine Corps (USMC) in the Pacific until the end of the war and a batch of 170 were provided as Lend-Lease to the British Army, who issued them as ‘accompanying guns’ for Armoured Car regiments. The M3 GMCs served with the British Armoured Car regiments in North Africa, Sicily, Italy and France until they were replaced by ICS armoured cars in 1944.

However, the TDF’s commander, Colonel (later Major General) Andrew D Bruce, favoured an even more aggressive tactical doctrine, which led to analysis of over 200 different designs to develop a new 3-inch (7.62mm) ATk gun[25]. The result was the 3-inch M5 Towed and M7 Vehicle guns; the latter being mounted in a new open-top turret on an M4 Sherman chassis to create the M10 Wolverine GMC. A further-development of this gun, known as the 76mm M1 ATk Gun, was mounted on an entirely new chassis to create the first dedicated US TD – the M18 Hellcat GMC[26].

M18 Hellcat

The M18 Hellcat GMC proved to be one of the best examples of the TD concept as it weighed half as much and was smaller than the M10 Wolverine GMC but had a more powerful gun and was the fastest tracked vehicle of the war. Towards the end of the campaign in Europe, there were fewer and fewer opportunities to engage Panzers and enthusiasm for the TD concept dwindled. Nevertheless, the US TDF destroyed 1,500 tanks and other AFVs, 684 ATk guns, 614 machine-gun posts, 668 bunkers and 18 aircraft following D-Day.


However, in a reverse of German experience, the TDF increasingly provided fire support for US Infantry divisions as a result of the lack of Panzer targets; although, as ‘ICS specialists’, they performed this role equally well. By 1945, many M18 Hellcats were serving with conventional armoured formations; effectively being employed as light tanks and Assault Guns. This was reflected by General George S Patton’s instructions to the 3rd US Army: “Self-propelled anti-tank weapons should be held in reserve to intervene against enemy armoured attacks. They should locate routes to and firing points from probable sites of future activities. Anti-tank guns should be trained to fire as field artillery and be provided with a large proportion of high-explosive shells[27].

The Red Army was also impressed by the Assault Gun concept and began to develop their own designs; known as Samochodnya Ustanovka (SU) or self-propelled (gun) mounts. As Russian artillery was always considered to have dual Indirect Fire (IDF) and ATk roles, the Assault Gun was a natural fit for Red Army doctrine.  The first design was the SU-76, which mounted the 76.2mm ZIS-2 gun on a modified T-70 light tank chassis, which was augmented by US 57mm T-48 GMCs (known as the SU-57 to the Red Army), delivered under the Lend-Lease scheme. These were, subsequently, replaced by 85mm and 100mm guns mounted on modified T-34 tank chassis (known as the SU-85 and SU-100 respectively), plus 122mm and 152mm guns on Joseph Stalin heavy tank chassis (known as the JSU-122 and JSU-152 respectively).

The Soviet SU-85 Assault Gun was based on the T-34 tank. Impressed by other designs, the tank destroyer concept was a natural fit with Soviet doctrine.

After the war, the Assault Gun and TD concepts were largely abandoned by the West, but the Soviet Union continued to produce ‘SU guns’ to support Airborne and Naval Infantry; such as the 57mm Aviadesantnaya (‘Air Descent’) SU(ASU-57), which entered service in 1951 (replacing the SU-76), and ASU-85, which replaced the ASU-57 in 1959. The ASU-85 was, subsequently, replaced by the Boyevaya Mashina Desanta (BMD) or ‘Airborne Combat Vehicle’ family in 1969, including the 2S25 Sprut-SDKraken’ armed with a 125mm 2A75 smoothbore gun. At the same time, other forces were producing wheeled AFVs mounting heavy-calibre weapons, such as the Alvis FV601 Saladin armoured car, and the French GIAT (now Nexter) AMX-10RC Roues-Canon (‘wheeled gun’) armed with a 105mm F2 rifled gun. These platforms represented the ‘Third Generation’ of the wheeled Assault Gun, FSV and MGS.


By comparison, following the withdrawal of the 6×6 Alvis FV601 Saladin armoured car in 1993, the British Army’s Mech Inf battalions, equipped with the GKN 4×4 Saxon APC had no greater fire support capability than that of a Light Role Battalion. The Saxon APC was only equipped with a pintle or Anti-Aircraft (AA) mount for a 7.62mm General Purpose Machine-Gun (GPMG), although a small number were fitted with Peak Engineering L37 GPMG turrets. However, there were almost no situations when they could make use of fire support from their vehicles. In terms of artillery, Mech Inf formations were provided with batteries equipped with towed 105mm L118 Light Guns, which had the benefit of very low safety distances, optimised for supporting dismounted infantry as highlighted by employment within 40-50m of troops during the Falklands War (1982), but very limited mobility.

During the mid-1990s, however, the Royal Artillery planned to replace the 105mm Light Gun with the 155mm Light Mobile Artillery Weapon System – Gun (LiMAWS-G)[28].  Whilst this offered potential benefits from using common ammunition, it created a mismatch in capability between the Mech Inf (Saxon) battalions and the 155mm AS90 self-propelled howitzers allocated to the Mech Inf brigades, since the safety distances were much larger for the heavier guns.

The Light Mobile Artillery Weapon System (LIMAWS(G)) 155 mm Portee was intended to provide a complementary capability to the AS90 155 mm SPG and to replace the 105 mm Light Gun. Based on the M777 towed howitzer, it was mounted on a Supacat HMT platform. Ultimately, the concept was cancelled to save money.

Mech Inf battalions also suffered from sub-optimal organic capabilities as a result of being equipped with 81mm L16 mortars carried in stowage racks in the rear of standard APCs, which had to be dismounted from the vehicle for firing. This slowed the mortar platoons’ into/out of action times and increased their vulnerability to counter-battery fire. In addition, the maximum range of the 81mm mortar (5650m) meant that they were rapidly out-ranged during anything more than a very deliberate advance. These and other weaknesses were highlighted as follows:

We would make an off-the-wall suggestion: first, accept that the day of the 81mm mortar in mechanized warfare is over. Next, take on board the fact that the Israeli Army mounts 60mm mortars on its MBT and a variety of other AFV, and adopt a policy of holding a lot of light mortars, on squadron/company vehicles, for quick action high angle fire in the company-level battle. We like the idea of the 60mm rather than the 51mm both on account of range (2000m) and effectiveness. Now think about filling the roles of both the missing artillery close support and the present battlegroup level mortars in the armoured and mechanised brigades by a brigade level unit equipped with what the Russians term a ‘combination gun‘ (2S9/SO-120) – a breech-loading 120mm mortar in an SP mounting. Crucially, these are capable of firing in both upper and lower registers, and are therefore more suitable than normal mortars for the support of dismounted infantry assault (120mm is also a calibre in which a reduced-effect projectile is less of a logistic nonsense than trying to do the same thing, as has been suggested, at 155mm)[29].

The function of an APC/IFV is to launch infantry against other infantry fighting as infantry, and not to become involved in fighting other IFVs while it is doing so. The primary function of its armament is to enable it to carry out this mission – by preventing its prime opponent, the enemy’s infantry, from negating it. There are a number of weapon fits which lend themselves to this primary function… This could involve solutions ranging from rifle-calibre machine guns alone to a variety of HE weapons including rapid-fire cannon, automatic grenade launchers, light mortars, and at the extreme, the SdKfz 251/9’s short 75mm howitzer. If an anti-armour capability is required, then it should be secondary to the neutralization weapon. Our own preference leans towards the 20mm cannon/rifle-calibre MG combination as offering the best all-round performance[30], which wins by a short head from twin MGs; we have also previously expressed our liking for a scaling of light mortars on a one per vehicle basis[31].

The 75 mm Stummel was another innovative German concept and created what was effectively the first IFV.

The 75mm Stummel (‘stump’) howitzer, mentioned above, was an ‘ICS gun’ mounted on the SdKfz 251/9 halftrack. This was same weapon that was mounted on PzKpfw III/IV ‘ICS tanks’, wheeled armoured cars and early versions of the StuG III. The same weapon system, with a new longer (L/48) barrel, also provided an effective anti-armour capability and the utility of such a vehicle was highlighted in a BAR article promoting a Future Assault Gun (FUSTUG), which described it as “the ideal SP assault gun for close support of infantry[32]. The concept stemmed from a paper written by Sydney Jary in 1946, but the idea stalled following disagreements over whether the vehicle should be operated by the Artillery or Armoured Corps. Jary summarised the capability need, as follows:

There has always been a requirement for an armoured assault gun to support infantry in the attack and, for the British Army, this need has yet to be fulfilled. In WW2, we used what tanks were available to support us, but now, with our battle tanks so big, sophisticated and costly, the requirement for a latter day Sturmgeschutz may be pressing indeed[33].

The move towards larger calibres in indirect fire weapons, and consequently larger troop safety distances, has increased the importance of direct fire support for assaulting infantry.  And the unsuitability of the tanks of 1944-45 for the intimate support role has been compounded by developments in tank design over the last fifty years.  The effect of trends in this area was summarised in a Tank Museum pamphlet, “Fire & Movement”, of 1975, which stated: ‘The effect of half a century of tank evolution has been to shift the emphasis from general purpose armament to specialised armour defeating weapons.  This now makes it very difficult for the modern tank to carry out many of the tasks which earlier tanks could once fulfil fairly easily.  The tasks still remain, however, and they must now be done by the different types of ‘non-tank’ AFV which have been developed in the last few years[34].

FUSTUG’s primary employment is to provide intimate fire support in any tactical situation involving movement by dismounted infantry (of any persuasion) in actual or anticipated contact.  Secondary functions are to substitute for tanks in the firebase role firing direct or semi-direct; to thicken up indirect fire plans; and, in defence, to form part of the anti-armour plan.  In the assault, we see the numbers required as a four-vehicle troop/platoon per assaulting company, or one per platoon and one reserve.  In peace support operations, the incorporation of FUSTUG into armoured or mechanised infantry battlegroups would provide a capability for direct fire support greater than that of Warrior without either the practical or the political problems accompanying the deployment of MBT…[35]

The FUSTUG concept was included in subsequent BAR articles on infantry firepower, which concluded that there was: “no substitute for rapid destructive direct fire support from an SP assault gun…[36]. The concept was also revised in a paper on urban operations, which incorporated a 120mm BL mortar, rather than a traditional gun/howitzer, which had: “the advantage of being an available weapon, which is already proposed as a combined replacement for the 81mm mortar in mechanised warfare and as a filler-in of the gaps in close support capability resulting from the universal adoption of 155mm tube artillery[37].

03. Modern Assault Gun Development

In the 1970s, Thyssen-Henschel (now Rheinmetall) produced the Tanque Argentino Mediano (TAM) for the Argentine Army; based on the Marder (‘Martin’) IFV. The company also offered a version, known as the TH-301, for export to Malaysia (1981), Thailand (1985-86) and Ecuador (1988). Whilst these were offered as Medium tanks, armed with Rheinmetall Rh105-30 rifled guns in three-man turrets, there was also a Marder Fire Support Tank armed with a 57mm Bofors gun[38]. However, these platforms arguably represented the nadir of the tracked ‘medium tank’ and the rise of a ‘Fourth Generation’ of the wheeled Assault Gun, FSV and MGS, which took advantage of significant advances in wheeled AFV technology.

The Thyssen-Henschel TAM medium tank was based on a Marder IFV with a Leopard 1 MBT turret mounting a 105 mm gun.

South Africa was one of the first to develop a new wheeled Assault Gun in the form of the RMC Reumech (now Denel) 6×6 Rooikat. Like the Marder Fire Support Tank, the Rooikat uses the 76mm GT4 gun an alternative to the traditional tank gun; based on the OTO-Breda ‘Super Rapid’ naval gun. Although a more-traditional 105mm gun is available for export variants, the South African National Defence Force (SANDF) has found the 76mm GT4 gun effective enough during its many ‘Bush Fire Wars’. The use of the GT4 on Rooikat also reflects a trend in other modern platforms, which use similar ‘heavy autocannons’ such as the Russian 57mm BM-57[39].

The Italian Army was one of the first European armies to procure a wheeled ‘heavy DF’ vehicle to equip its mechanised cavalry regiments in the 1980s. Ten 8×8 prototypes with a 105mm tank gun were built by Societa Consortile IVECO OTO-Melara (CIO) in 1987-89 and the design was adopted as the CIO Centauro B1 in 1990. A total of 400 vehicles were delivered to the Italian Army by 1996, followed by exports to Oman and Spain[40]. The US Army also leased 16 vehicles in 2000-02 for experimentation and TTP development prior to the introduction of the M1128 Stryker MGS. Italian Centauro B1s have deployed on operations in the Former Yugoslavia, Iraq, Lebanon and Somalia, where they have demonstrated considerable operational mobility and reliability[41].

Iveco-OTO-Melara Centauro B1 mobile gun system has defined a new class of wheeled assault gun / tank destroyer. It has been so successful in Italian service that it has given way to a new version, the Centauro 2, mounting a 120 mm gun.

Although it entered service first, the Centauro featured an APC/IFV-style layout with a front-mounted engine and rear access ramp; facilitating ammunition re-supply and allowing the Centauro to carry a four-man ‘close defence’ team (although ammunition stowage is reduced). Subsequently, CIO developed the 8×8 Freccia (‘Arrow’) Veicolo Blindato Medio (VBM), armed with a 25mm cannon in a two-man HITFIST turret, the Draco (‘Dragon’) SP AA Gun (SPAAG), armed with a 76mm OTO-Melara ‘Super Rapid’ gun, and the 155mm Porcospino (‘Porcupine’) SP Howitzer. Together with Freccia VBM and its supporting variants, Centauro has provided the Italian Army with an comprehensive family of wheeled, medium armoured vehicles based around what has been re-categorised as a ‘Mechanised Cavalry’ or Combat Recce Vehicle (CRV).

In the late 1990s, the Multi-Role Armoured Vehicle (MRAV) programme also included requirements for a heavy FSV or MGS; also known as the Véhicule Porteur de Système d’Arme (VPSA) or Radkampfwagen 90 (RKfw 90) by the French and German armies respectively[42]. A French Concept Demonstrator, known as the Vextra VPSA, was produced by GIAT (now Nexter) and has been offered for export to a number of Middle East and North African (MENA) countries[43]. Daimler-Benz also produced the RKfw 90 Concept Demonstrator based on an 8×8 Experimental Fahrzeug fitted with a Leopard 1 turret with a 105mm gun[44].

Following the development of these wheeled ‘Concept Demonstrators’, several vehicles have entered service as a ‘Fifth Generation’ of the wheeled Assault Gun, FSV and MGS. As a result, tried and tested components are available and have been used by other Original Equipment Manufacturers (OEM) to create different platforms, including (but not limited to) the following:

  1. In 2018, the Italian Army contracted CIO to deliver 136 Centauro B2 vehicles with OTO-Melara (now Leonardo) HITFACT turrets, 720hp engines and enhanced survivability. The HITFACT 2 turret weighs up to 7 tons (dependent on protection levels) and can be fitted with an automatic-loader (reducing the crew size from four to three) for either a 105mm gun or the new 120mm Low Recoil Force (LRF) weapon used on the Italian Centauro B2.
  2. Alternative turret systems include the Cockerill Industries CT-CV 105HP turret, armed with the British L7 or US M68 105mm gun, which has been mounted on the General Dynamics European Land Systems (GDELS) ASCOD 2 tracked AFV and a number of wheeled AFVs, including (but not limited to): the GDELS Pandur and Piranha AFVs; the Finnish Patria Armoured Modular Vehicle (AMV); Polish Rosomak (‘Wolverine’) WWO Wilk(‘Wolf’); and US Cadillac Gage (now Textron) 4×4 and 6×6 Commando family of vehicles.
  3. Another Cockerill turret is the XC8 105-120HP, which can integrate 105mm or 120mm NATO-standard weapons and has been fitted to the Brazilian Guarani VBE; Taiwanese CM-32 Yunpao (‘Clouded Leopard’) FSV; and Polish WWO Wilk 2 MGS platforms[45].

The development of these platforms reflects the emerging requirements of several different nations, to provide a wheeled medium force with mobile direct and, potentially, indirect fire support. While a Mechanised force generally cannot withstand a concentrated armoured assault, NATO tests and exercises have shown that the addition of Assault Guns, armed with 105mm or 120mm weapons, significantly increases their ability to defeat the enemy. These concepts were tested by the Polish Army Officers’ Academy, which concluded that attaching Assault Guns to a Mechanised force could: “enable the formation to stop an enemy tank advance in its tracks[46].

Although Great Britain and France left the MRAV/VBM programme, the German GTK entered service as the ARTEC Boxer in 2009[47]. Boxer is currently in service with Germany and the Netherlands as an APC, but Australia has procured a variant armed with a 30mm cannon in a Rheinmetall ‘Lance’ turret to meet its CRV requirement and Lithuania is also introducing Boxer as an IFV armed with a 30mm Bushmaster cannon in an Israeli Samson remote turret. Whilst these are only medium-calibre applications, a 155mm Remote Control Howitzer (RCH-155) has also been developed for Boxer, which indicates that the platform is capable of tolerating the recoil forces of a 105mm or 120mm DF gun. The RCH-155 turret can also be mounted on the GDELS ASCOD-2 chassis, potentially providing both a wheeled and a tracked IDF capability.

Current Assault Guns. Several different wheeled Assault Guns are currently in service with at least 18 nations and have been produced by others including (but not limited to) the following[48]:

Country Platform Weapon Remarks
Austria Steyr (GDELS) Pandur 2 105mm Cockerill CMI CT-CV 105HP turret on 8×8 Pandur 2 in service with Portugal (30).
Brazil VBE Guarani


105mm Cockerill CMI CT-CV 105HP turret on 6×6 SuperAV chassis.
China NORINCO Type 02 (PTL02) 100mm Type 86 smoothbore 8×8 Type 92 AFV variant in PLA service since 2004.
Cuba BTR-116 100mm D-10T (rifled) Modified (lightened) T-54/55 turret on BTR-60PB chassis
France GIAT (Nexter) AMX-10RC 105mm F2 (rifled) In French service (300) since 1979. Exported to Morocco (198) and Qatar (12).
GIAT (Nexter) Vextra VPSA 105mm G2 Prototype: TML-105 turret on 8×8 VBCI chassis. Trials with MENA countries.
Germany Daimler-Benz RKfw90 / Thyssen-Henschel TH-800 105mm Rh105 Prototypes with Leopard 1turret on 8×8 chassis.
Italy CIO Centauro B1


105mm Oto-Melara In service with Italy (300), Jordan (141), Oman (9) & Spain (82).
CIO Centauro B2 120mm Oto-Melara Italy has 74 (of 150) B2 with Oto-Melara (Leonardo) HITFACT-2 turret.
Japan Type 16 Manoeuvre Combat Vehicle (MCV) 105mm L7 Prototype: Technical Research & Development Institute (TRDI)[49].
Poland WWO Wilk 105mm CMI XC-8 105/120HP turret on 8×8 Rosomak chassis.
WWO Wilk 2 120mm
Russia / Soviet Union 2S14 Zhalo (‘Sting’) 85mm 2A62 Prototype (1970): on BTR-70 chassis (Cuban BTR-116).
South Africa Denel Rooikat



76mm GT4 In service with the SANDF since 1991. Bespoke chassis with 76mm GT-4 gun (76mm Oto-Matic naval gun). Export variants with 105 gun.
Denel Rooikat 105



105mm GT7
Switzerland MOWAG (GDELS) Shark 105mm G2 or L7 Prototype: TML-105 turret on 10×10 “Piranha” chassis.  Also fitted to 8×8 “Piranha”.
Taiwan (Republic of China) CM-32 Yunpao FSV 105mm or 120mm Cockerill FSV variant of 8×8 CM-32 Yunpao IFV[50].
Turkey / UAE Otokar / Al Jasoor 8×8 Rabdan 100mm 2A70 BMP-3 turret on Otokar 8×8 Arma chassis for UAE.

Trials with Cockerill 105HP[51].

United States Textron LAV-600 Commando 105mm L7/ M68 LRF Stingray light tank turret on 6×6 Commando chassis.
Textron LAV – Assault Gun


105mm L7/ M68 LRF Textron turret (as above) on 8×8 LAV chassis for USMC.
M1128 Stryker MGS 105mm M68A2 Based on 8×8 Stryker APC in service with US Army.


General Dynamics Land Systems Griffin III MFP  prototype is a contender for the US Army’s Mobile Protected Firepower requirement. This mounts a 105 mm gun in a modified Abrams turret on an IFV platform. Though new, it is the latest incarnation of a concept first conceived in 1938. Even so, it is likely to add considerable firepower to US Army Infantry Brigade Combat Teams (IBCTs) (Image: GDLS)

04. Conclusions

It is clear that the Assault Gun has considerable historical precedent as a means to provide mobile fire support to ‘medium forces’, dating back (even before the advent of mechanisation) to the use of Infantry guns and Pack howitzers; especially in ‘complex terrain’ such as urban, mountain and jungle conditions. Over time, these have developed into (and from) self-propelled ATk guns and TDs, which provided an additional, but secondary role. Whilst an Assault Gun, FSV or MGS should never be used as an alternative to or a replacement for a tank, they can provide ‘emergency’ anti-armour capabilities if required – particularly for Mech Inf forces that do not plan to go ‘toe-to-toe’ with armoured forces, but are sometimes unlucky enough to encounter them[52].

Some common themes from past and present Assault Guns are as follows:

  1. Selection of Assault Gun armament as a balance between ‘infantry close support’ and anti-armour weapons. Both can be effective, but it is essential that the armament can fire both a reasonable AP and an effective HE shell;
  2. Heavy (120mm) AMS are a potential alternative to more-traditional guns and howitzers, since they offer the potential to deliver both DF and IDF capabilities;
  3. Wheeled platforms make good Assault Guns for supporting Mechanised forces. If you go to the trouble of producing a tracked platform, then you may as well produce an ‘ICS tank’ rather than an Assault Gun. Wheeled platforms also provide excellent operational mobility and reliability with a reduced logistic burden (compared to tracked vehicles);
  4. Wheeled Assault Guns, FSVs or MGS can provide effective fire support or act as ‘medium armour’ for Light, Marine/Naval and Air Assault infantry operations. The ability to deploy a small ‘medium armour’ force by air in support of Light Forces is a key capability;
  5. The use of Common Base Platforms and other common components, such as common weapons and ammunition natures, will reduce logistic and training burdens.


Operational experience made Sturmartillerie an effective and versatile force. Their TTPs are illustrated in the following extract from the Assault Gun Commander’s Handbook (1944)[53]:

1. General Principles. Assault Guns have the task of providing immediate direct support for the infantry in all situations in the forward zone of action, beating down and suppressing the enemy’s heavy weapons fire with that of their own.

  • The Assault Gun combines firepower with mobility and shock action. Its protected weapon system and immediate direct fire capability enables it to accompany the infantry anywhere on the battlefield, providing them with close physical and moral support. Concentration is a special feature of their operations; abandonment of this principle leads to unnecessary loss.
  • In every action the destruction of the enemy’s tanks is a consideration of the utmost importance. Nevertheless, Assault Guns must not be solely employed as Tank Destroyers.
  • In the counter-attack role, Assault Guns are suitable for employment as a shock reserve against enemy tank attacks or penetrations of friendly lines. As the spearhead of the advance or pursuit they can quickly overcome points of resistance.
  • When breaking-off action and disengaging, Assault Guns, by virtue of their mobility and firepower, are the mainstay of the rear guard.
  • A temporary application of fire for specific bombardment in the forward battle zone is permissible, provided other artillery units are unable to fulfil this task, and provided it does not interfere with the Assault Guns’ primary mission. In such situations, Assault Howitzers will undertake the fire task[54].
  • Assault Guns are unsuitable for employment in static situations. Their only suitable and sensible function is close co-operation during infantry, mechanised or tank operations.

2. Employment. For operations, Assault Guns should be placed under the command of infantry or mechanised formation, and occasionally a tank formation; employment under the command of units smaller than a Battle Group is the exception.

  • The formation commander must be made aware of the Assault Gun’s characteristics, so that the maximum benefit can be obtained for the operation. The concentrated fire and shock effect of the whole Assault Gun force working on a narrow front produces the best results.
  • The tactical structure is the Assault Gun sub-unit. To parcel out guns in troops or singly impairs the mass fire effect and assists the enemy’s defence. Support of the infantry by single troops must, therefore, be limited to exceptional cases, and the troop promptly returned to sub-unit control at the conclusion of the operation. Employment of single Assault Guns in the forward zone should never take place, since Assault Guns are designed to provide mutual assistance for each other in circumstances of tactical or technical difficulty.
  • The more surprise the Assault Guns can achieve, the better will be the result. The approach march and final preparations are best made by night, the noise muffled by loudspeakers or artillery fire. Assault Guns will not take part in the preliminary artillery bombardment.
  • The Assault Gun commander will arrange for replenishment and technical assistance facilities to be available in the forward zone and assess the correct moment for the Assault Guns to be withdrawn to their rally point.

3. Co-operation with Infantry
. Infantry must make full and immediate use of the Assault Guns’ fire support. Fire and movement between Infantry and Assault Guns must be mutually agreed. The best results are obtained when the Infantry and Assault Guns adopt a loose formation. As the Assault Guns will attract the enemy’s fire, the Infantry should not crowd together behind them, as this will result in heavy casualties; instead, the Infantry should advance by a series of carefully timed advances[55].

  • Co-operation between Assault Guns and the Infantry’s heavy weapons must be agreed in advance, particularly in cases where the former are at risk from the enemy’s anti-armour weapons.
  • In open country, the Assault Guns will lead the advance; where the country is closer, Infantry will take the lead. In the latter case, it is the Infantry’s responsibility to warn the Assault Guns of any obstacles in their path, such as minefields, bad going and enemy positions. Mutual identification of targets can be achieved by means of tracer ammunition, flares, indicative measures and hand signals. The Assault Gun and Infantry commanders should remain in the closest contact throughout the action.

4. Co-operation with Field Artillery. As the fire of Field Artillery is supplementary to that of Assault Guns, strict co-ordination of their respective fire plans is essential[56].

  • Assault Guns are responsible for ensuring that supporting artillery fire is put to its best use; keeping the Field Artillery in contact with the spearhead of the attack; and providing early warning of defensive fire tasks that might be required.
  • The Field Artillery are responsible for neutralising the enemy’s artillery and fire control posts; preparing the way for the attack and protecting its flanks; and providing protection for the recovery of Assault Guns which have become casualties.
  • The co-operation of Assault Guns with the Artillery Fire Controller is, however, a supplementary task and must not distract from the principle mission of providing direct fire support for the infantry.

5. Co-operation with Engineers. Close co-operation between Assault Guns and Combat Engineers prevents casualties and losses. Under cover of the Assault Guns’ fire, the Combat Engineers will create minefield gaps, fill-in anti-tank ditches and strengthen damaged bridges. During an attack against prepared positions, each Assault Gun unit will be allotted engineers for the duration of the operation. Assault Guns are outstandingly suitable for the support of Combat Engineers in all manner of battle situations.

6. Co-operation with Air/Aviation. The involvement of Air/Aviation in the ground battle will benefit the Assault Guns by causing confusion among the enemy and by raising dust and smoke clouds. In order to advise the support squadrons as to the position of the front line, Assault Guns will put out smoke markers, and by firing smoke or tracer ammunition to advise aircraft of suitable targets. For co-operation with Air/Aviation, the Assault Gun unit will be equipped with Ground-to-Air communications.

7. Tasks for Escort Troops[57]. The first duty of Escort Troops is the protection of the Assault Guns in all phases of the battle. Escort Troops are not assault troops; they are neither armed nor able to perform this role, having a specialised task to perform. As well as providing a close escort for the Assault Guns, Escort Troops will: indicate targets by tracer fire or other signals[58]; warn the Assault Guns of anti-armour weapon positions, minefields and other obstacles; secure the route to the operational start line; and protect the Assault Guns in their harbour areas. Once allocated to a particular Assault Gun, Escort Troops will remain with it throughout the action. If they are in danger of falling behind, they will attract the commander’s attention and do their utmost to regain contact. Should the establishment of the Assault Gun unit not include Escort Troops, the infantry will be tasked to provide a sufficient number of personnel to perform the task.

8. Enemy tanks. Should Assault Guns encounter enemy tanks, they are to be engaged. Measures to be taken include the construction of a fire-front and engaging the flanks of the enemy tank formation. Where the enemy attack is accompanied by infantry, these will be engaged by Assault Howitzers [or other indirect fire assets, such as mortars], while the remainder of the Assault Guns concentrate on the tanks; this will have the effect of separating the enemy infantry from their armour. For this type of action, an internal troop organisation of one Assault Howitzer and two Assault Guns is particularly suitable.

9. Terrain and Weather. The shape of the ground, the nature of its covering[59] and the type of going all influence Assault Gun operations. Full utilisation of terrain increases weapon capabilities, decreases losses and saves wear on equipment. Service with Assault Guns is arduous and, therefore, measures to protect Assault Gun crews from climatic extremes are required.



[1] David Gates: “Western Light Forces & Defence Policy” – Volume 1 (University of Aberdeen); p51.

[2] Gates: Ibid; p12. The best-known example is Tarleton’s Legion from the American Revolution.

[3] At this time the ‘Artillery Train’ (the Royal Artillery) comprised only four ‘battalions’ of heavy guns.


[5] The US purchased 50 guns in 1899, followed by another 120 in 1904, which remained in service until 1941. Around 50 were used by the Philippines Scouts and their US advisors against the Japanese.

[6] Like the British,

[7] Due to shortages of modern equipment, 50 US TRP guns were used during the Pacific campaign (1941). French and Polish guns captured in 1940 were used as the 3.7cm Infanteriegeschutz 152(f) by the Germans.

[8] These were known as: 15cm sIG33 auf PzKpfw I (‘Bison 1’); the 15cm sIG33 auf PzKpfw II (‘Bison 2’) on a ‘stretched’ PzKpfw IIchassis; and the 15cm sIG auf PzKpfw 38(t) ‘Grille’ (‘Cricket’) on a Czech vz38 chassis.

[9] British ‘trench guns’ included the Ordnance QF 1.59-inch BL Vickers-Crayford Mark II ‘rocket gun’, which was used experimentally as an aircraft weapon.

[10] During Operation PLUNDER, a troop of 3.7-inch QF Pack Howitzers from 414 Mountain Battery crossed the Rhine in BuffaloLanding Vehicle Tracked (LVT) to support 1 GORDONS. The Pack Howitzer was the only gun able to fit inside an LVT and provided DF support to the infantry during urban fighting; including use from the upstairs room of a house. Martin Lindsay: “So few got through” (London, 2000); p222-223.

[11] Zaloga: “Staghound Armoured Car 1942-62” (p27-28). A T17E3 Howitzer Staghound prototype was fitted with a US 75mm M8 ScottHowitzer Motor Carriage (HMC) turret, but did not enter production (p19-22).

[12] Compared to 112mm (using AP shells) or 160mm (using AP Discarding Sabot shells) by the 6-Pounder at the same distance. The US M2/M3 was based on the old French 75mm M1897 field gun.

[13] Zaloga: Op cit (p22). Although only 32 were produced, the Staghound Mark III (ICS) was “probably the best 75mm armoured car available”.

[14] A High-Explosive ATk (HEAT) round was developed for the Burma campaign (1944) but rarely used as the Japanese tank threat had all-but disappeared by this time.

[15] Five regular artillery, five Territorial artillery and five Territorial infantry units were converted in 1938/39.  The Territorial units were ‘doubled’ in 1939; giving a total of 100 ATk batteries by the start of the war.

[16] Each ATk Company was equipped with nine guns; usually French 25mm Hotchkiss guns (as the Divisional ATk Regiments had priority over the new 2-Pounder QF ATk guns). In 1941/42, these were divided into Battalion ATk Platoons; initially with three 2-Pounders, but subsequently with three 6-Pounders.

[17] This reflected the limitations of the 25mm Hotchkiss ATk gun, which was too light to tow.  However, it also mirrored the practises of the French Foreign Legion’s Batterie Saharian in the 1920s.  The French Army also developed a self-propelled version of their 47mm Model 1937 ATk gun on a 6×6 Laffly W15T truck; known as the Tracteur Chasseur de Char (TCC) or ‘Tank Hunting Tractor’.

[18] Around 175 Deacon SP guns were produced in 1942-43 but withdrawn in 1943. Some were converted into protected gun limbers but the remainder were sold to Turkey.

[19] Guderian: “Panzer Leader” (Boston 1996); p297.

[20] Large-scale manufacture of the latest 75mm M1A1 Pack Howitzer, 105mm M2 Field Howitzer and 37mm M3 ATk Gun designs only began in 1940.

[21] A total of 918 guns were converted from July 1940 to November 1941. The basic design work had already been undertaken to modernise these old but effective guns by mounting them on new M2A3 carriages and fitting them with DF sights. This design mirrored a similar upgrade by the French Army and modified French and Polish M1897 guns were known as the 7.5cm PaK 97/38 by the Germans.

[22] The 75mm M3 GMC was an M1897 on an M3 halftrack, whilst the M5 GMC was the M1897 on a Cletrac tractor. The 37mm M6 Fargo GMC consisted of an M3 ATk gun on a ¾-ton Dodge WC52 utility truck.

[23] The M8 was an M2/M3 (AFV variant of the M1A1 Pack) Howitzer mounted in an M5 Stuart light tank. The M7 Priest was a 105mm Field Howitzer mounted on a turretless M3 Grant medium tank chassis.

[24] The M5 performed so poorly during trials that the TDF refused to accept it. However, 5,380 M6 Fargo GMCs were produced in April-October 1942 and used by 601 and 701 TD battalions in North Africa (1943), but found to be ineffective against German Panzers. Some were sent to the Pacific in 1944 where they were more effective against Japanese tanks and bunkers. Several units transferred the guns to spare M3 halftrack, but the 37mm M1 was obsolescent and they were due to be replaced by the 57mm T-48 GMC.

[25] Illustrated by the TDF moto (Seek, Strike and Destroy) and badge of a panther crushing a tank in its jaws.

[26] The 76mm M1 Gun fired the same 3-inch projectile as the M5/M7 Gun but used a different shell case and was, therefore, re-classified as a 76mm weapon to avoid confusion.

[27] Quoted in Ian Hogg: “Tank Killing – Anti-Tank Warfare by Men and Machines” (London 1996); p11.

[28] LiMAWS-G consisted of a 155mm M777 (Royal Ordnance) Light Towed Howitzer carried en portée by a Supacat 8×8 HMT platform.

[29] Sydney Jary & ‘Carbuncle’: “Gunners” in British Army Review (BAR) 116 (August 1996); p27.  It was noted that Royal Ordnance(now BAE Systems) produced a 120mm Automatic Mortar System (AMS), with a range of up to 1200m, able to be fitted to a variety of AFVs. The 120mm AMS was adopted by the Saudi Arabian National Guard (SANG) and mounted on their 8×8 Light Armoured Vehicles (LAV).

[30] 20mm was seen as a useful all-round calibre due to its combination of HE capability; high rate of fire; and reasonable ammunition capacity. Therefore, it offered a balance between neutralization, air defence and anti-armour capability but 20mm guns are now obsolete and unable to defeat even light AFVs.

[31] Jary & ‘Carbuncle’: “A mitigated blessing: Protected Mobility for Infantry” in BAR 118 (April 1998); p40.

[32] Jary & ‘Carbuncle’: “Sturmgeshutz – A Yesterday Solution to a Today Problem” in BAR 113 (Aug 1996).

[33] Ibid; p5.

[34] Ibid; p7.

[35] Ibid; p9-10.

[36] Jary & ‘Carbuncle’: “Firepower at Platoon and Company Level” in BAR 114 (Dec 1996); p15.

[37] Jary & ‘Carbuncle’: “In the Jungle of the Cities: Operations in Built-Up Areas” in BAR 121 (Apr 1999); p49.

[38] The 57mm Bofors ‘support tank’ gun was based on the 57x438mm naval and AA gun. This concept reflected earlier use of AA guns, including the famous 88mm Flak gun, in German armoured vehicles.

[39] The BM-57, a variant of the Soviet 57x348mmR S-60 AA gun, has been fitted in the AU-220M Baikal remote turret on BMP-3 and T-15 Amata IFVs, as well as a ‘TD variant’ of the 8×8 K-17 Bumerang IFV.

[40] Oman received nine modified vehicles with 120mm guns in 2008, with options for up to 25 additional vehicles. Spain received 84 Vehículo de Reconocimiento y Combate de Caballería (‘Cavalry Combat Recce Vehicles’), plus four Vehículo de Recuperacion(‘Recovery’) variants, in 1999-2006. Subsequently, Jordan has received 140 ex-Italian Army vehicles donated as military aid.

[41] In Somalia, eight Centauro B1s averaged 8,400km over four months in 1992 without any serious issues.

[42] In the UK, the requirement was known as MRAV, but the programme included the French Véhicule Blinde Modulaire (VBM) and German Gepanzerten Transport Kraftfahrzeug (GTK) requirements.

[43] The French Army maintains a requirement for a DF platform to replace the AMX-10RC; despite its formal replacement by the Engin Blinde de Reconnaissance et de Combat (EBRC) ‘Jaguar’ with 40mm cannon.

[44] RKfw 90 was designed to replace the 8×8 Luchs (‘Lynx’) reconnaissance vehicle (designed by Daimler-Benz, but manufactured by Thyssen-Henschel), supported by evidence from the success of the French AMX-10RC with its 105mm gun. It led to the development of the TH-Series of wheeled AFVs by Thyssen-Henschel (now Rheinmetall), but no orders were forthcoming. These wheeled DF vehicles have their origins in World War 2 designs, such as the Sonderkraftfahrzeug (SdKfz) 234/2 Puma AFV, which mounted a Daimler-BenzVK1602 Leopard light tank turret on an 8×8 SdKfz 234 armoured car.

[45] These vehicles are generally categorised as FSV or MGS, such as the Polish Woz Wsparcia Ogniowego (WWO) and French VPSA, which both translate as ‘Mobile Gun System’.

[46]Rosomak needs Wolves – Army Officers’ Academy Analysis” in MSPO 2014 Extra Report (in Polish).

[47] ARTEC (Armour Technology) is a joint venture between KMW and Rheinmetall. KMW is now also part of a Franco-German consortium known as KMW-Nexter Defence Systems (KNDS).

[48] Platforms are listed by country of origin, but may be in service with other nations (see remarks). The 18 user nations are: Brazil; China; Cuba; France; Italy; Japan; Jordan; Morocco; Oman; Portugal; Qatar; Russia; Saudi Arabia; Spain; Taiwan; UAE; and the United States.

[49] The TRDI MCV was adopted by the Japanese Ground Self-Defence Forces, which will receive up to 300.

[50] CM-32 is based on 6×6 CM-31 developed as the Timoney Technologies (Ireland) Mark 8 AFV for the Taiwanese Army. In the 1990s, Timoney also collaborated on the Vickers 6×6 Mark 11 Viper Long-Range Patrol Vehicle (aka Border Patrol Vehicle), which evolved from the Timoney 4×4 Mark 8 and Vickers 4×4 Valkyr designs, fitted with a Vickers Mark 5 tank turret armed with 105mm L7 gun.

[51] The Arma and HEMA Engineering Industries Anafarta (Patria AMV) lost to the FNSS Pars 6×6 Komando (‘Command’) and 8×8 Scout, which were adopted as the Özel Maksatlı Taktik Tekerlekli Zırhlı Araç (ÖMTTZA) or ‘Turkish Land Forces Special Purpose Tactical Wheeled Armoured Vehicle’ in January 2020.

[52]Tanks are like a black tie dinner jacket. You don’t need them very often, but when you do, nothing else will do”. Attributed to Major General Kathryn Toohey, Head of Land Capability, Australian Army.

[53] Taken from Bryan Perret: “Sturmartillerie & Panzerjager 1939-45” (Oxford 1999); p14-18.

[54] Where possible, following re-structuring in 1943/44, Sturmartillerie batteries comprised two Assault Gun (each of four 75mm StuG) and one Assault Howitzer (with four 105mm StuH 42) troops to provide heavy direct and indirect fire respectively.

[55] With DF support from the Assault Guns.

[56] Since the Sturmartillerie was part of the German artillery branch, this was organic, however, the implication is that a modern Assault Gun force should be allocated artillery Fire Support Teams.

[57] From 1944, Assault Gun brigades included a Grenadier Battery (to act as escort troops) with an organic Assault Pioneer Platoon.

[58] Especially in close terrain; both urban and rural. The Handbook makes specific reference throughout of the difficulties encountered in sunflower fields; frequently encountered during the summer in Russia.

[59] Including natural or man-made cover.


  1. Really interesting article. A few thoughts. Could not the emergency anti-armour capability Rexer talks about in the conclusion be achieved by an ATGW integrated onto the RWS of, say, Boxer? To what extent would the 40mm CTA cannon on Ajax, in medium armour role, fulfil the assault gun function? What one be prepared to give up to afford an assault gun, on say an Ajax or Boxer platform?


  2. As per above, what a delightful read, when someone has done the ‘homework’. My not brllilant German would tell me that Panzerjaeger is a person (on anti-tank duties, regardless of the means he has been given for the job; can be mounted or dismounted) whereas an assault gun suitable for antitank use would be (and the term that was used for this in the text was the first mentioned) a Jagdpanzer.

    As many ‘pack’ guns/ howitzers are mentioned in the history bit, the brilliant German recoilless (?) 7.5cm GebG 36 does not make it. It was used on Crete (coming down along with the paratroopers) and in the hugely long behind-the-lines raid on the Murmansk railway (in which operation the German Brandenburg unit took two of them along in (!) two-man canvass canoes
    … stabilising pontoons needed to be fitted.

    Liked by 1 person

  3. Great article. Just a correction: the Brazilian Army does not have a single Guarani with a 105mm cannon. So far we only have the APC version and we are preparing to acquire the mortar-carrier version.

    At the moment we only have the EE-9 Cascavel reconnaissance vehicles with 90mm cannon. The Guarani 105mm would be a replacement, but so far we have not defined anything about it.

    Liked by 1 person

  4. Fantastic article. Really enjoyed it, thanks to the author. I have written in the past over at on the potential of modern breach loading 120mm mortars in the direct fire role, so I am glad the author mentions them.

    It is for me an interesting exercise in compare and contrast for the assault gun role:

    120mm Mortars:
    1. There are many automatic, semi-automatic or even manual versions of the market – BAe’s AMS demonstrates on a Warrior decades ago, Patria NEMO, Polish RAK etc.
    2. Short range ( c. 1.2 to 1.5km).DF with standard rounds, but the old French Thomson-Brandt “Gun-Mortar” had a DF round with a combustible cartridge case that gave greater velocity
    3. Specialist indirect anti-armour capabilities e.g. STRIX IR guided round
    4. Potential for Gun Launched ATGM with HEAT warhead of greater diameter than 105mm gun compatible versions
    5. Massive flexibility in the indirect fire role

    105mm Gun e.g. Cockerill 105
    1. Big enough HE round and longer range than the mortar in DF
    2. APFSDS and HEAT rounds still capable of taking out IFV’s below MBT protection levels
    3. Might get a Mobility / mission kill on even an MBT from sides / rear
    4. Potential for gun launched ATGM
    5. 10km range indirect fires as a bonus….

    The mortar option means that ammo can be standardized across even light forces (Supacat ATMP, MRAZR and other light platforms can carry them), but the separate gun for DF means a cheaper mortar solution might be used (there are many on the market). The problem is , we seem unlikely to find the budget to pay for either.

    Liked by 3 people

    1. Good to consider both side by side, as options.

      As for 120mm Mortars:

      2. Short range ( c. 1.2 to 1.5km).DF with standard rounds, but the old French Thomson-Brandt “Gun-Mortar” had a DF round with a combustible cartridge case that gave greater velocity
      3. Specialist indirect anti-armour capabilities e.g. STRIX IR guided round

      I think the 1 km direct fire goes with rifled (to be able to hit anything ( for starters), whereas the STRIX can only be used in unrifled (‘musket’) mortars?

      105mm Gun e.g. Cockerill 105
      1. Big enough HE round and longer range than the mortar in DF
      4. Potential for gun launched ATGM

      Cockerill has been including the Ukraine-produced missile for their gun for long and I have been surprised that there has been no take-up;
      of course, in a first-kill match the OpFor kinetic round will have arrived while ‘your’ missile is still on its way
      – still a better result than your 105 mm round just bouncing off

      Liked by 2 people

  5. I’ve subsequently seem pictures of 120mm Patria mortar on a Boxer hull. However it’s hard to know whether it’s actually been fully integrated onto the vehicle yet, or whether it’s just a concept option.

    Also are the 81mm mortars planned for mechanised infantry battalions to be fired from Boxer, or do they have to dismount to set up?

    Liked by 1 person

  6. Great article, just to say you really should correct “Alternative turret systems include the Cockerill Industries CT-CV 105HP turret, armed with the British L7 or US M68 105mm gun,” the cockerill uses their own gun manufactured in Distroff France part of GICAT group. The gun can reach significantly higher pressures than L7 or M68 and as others have commented it also has indirect fire of 10km & GLATGM. CMI state 30% growth potential but not for what.
    Looking to the future there’s no reason why smart rounds couldn’t be developed or the GLATGM improved with fire & forget. Hope AP can be slightly increased but at no less than 550mm penetration of RHA at 2km depending upon the make up of the armour this could include up to and including T72 possibly slightly above GLATGM similar penetration at 5km.
    I do like the system but with more development it could be even better.
    I would surely think it would be cost effective and gives a bit of everything. It’s also possible that some training could be done in France hopefully saving some more pennies on simulators etc. If the 30mm unmanned version could take CT40 there maybe more savings.

    Liked by 2 people

  7. A small correction: WWO Wilk is not in service in Polish Army. In fact, WWO Wilk was a temporary demonstration consisting of combining the turret with AMV (Rosomak) chassis. It was never thoroughly tested, beyond the demonstration and theoretical analysis in [46].

    Liked by 1 person

  8. Didn’t read this article. As soon as I saw the M18 listed as an assault gun and that the article was equating assault guns and tank destroyers as virtually the same I thought ‘no, this is a gutter press definition, nothing to see, move on quietly.

    Liked by 1 person

    1. It’s worth remembering that the StuG. III was an assault gun used as a tank destroyer and the M18 together with the M10 was a tank destroyer later used as an assault gun. The M10 was often used to fire in indirect mode. The M18 was also used as a bunker buster. For sure, some tank destroyer battalions were very against the M18 because it had paper-thin armour. Underlying this article is the need to define more exactly what an assault gun is or isn’t. Some would even describe the Matilda II and Churchill tanks as assault guns because they were “Infantry tanks” designed specifically to accompany attacking infantry and provide close support. Clearly, they were more than this. Others would say that ultimately, the British, American and German approach to AFV development reflected a common need for second tank type that was less expensive than primary tanks. Today, the term “Mobile Gun System” is essentially the same as an assault gun but avoids the debate about close support versus anti-tank roles.

      Liked by 2 people

      1. Yes. The respondent is being a bit churlish.

        Everyone wants a medium weight assault gun, except us…


      2. Nicholas,
        Noting your recent tweet :

        ‘The M18 Hellcat tank destroyer was introduced in 1943. It mounted a very large (76 mm) gun on a very small (16-tonne) chassis. Despite an open-top turret and paper-thin armour, it could defeat both Panther and Tiger I. Its top speed of 55-60 mph made it the fastest “tank” of WW2’

        I think the obvious question must be if it’s that good why isn’t it still in service? Seriously!


      3. The USA only made 1,800 M18 Hellcats and most were run ragged after eight months of continued fighting. I believe the M-18 was subsequently adopted by the Yugoslavian Army and remained in service until 1990. The main reason they weren’t retained in US Army service was because the US Army reduced its size with armoured units consolidated around a single universal tank type, the T-26, that became the M46/ M47/ M48. Patton.

        The Achilles heel of all US tank destroyers was thin armour and no turret roof. Many crews were killed or injured by air bursting artillery. The UK finally got around to producing a tank destroyer capable of mounting the Sherman Firefly’s 17-pounder gun. Called the A30 Avenger, it had a roof and was considered ideal. First prototypes only arrived in April 1945, too late to make it into full service. After the war, Britain too standardised around a single tank, the Centurion.

        The US re-visited the tank destroyer concept with the M551 Sheridan, which was designed as a light airborne support tank. It was fast, agile and packed a big punch with a 152 mm gun launcher that fired HEAT, HE incl. Cannister, and Shillelagh ATGM missiles. It wasn’t replaced when it went out of service, but the need remained. US Army Infantry Brigade Combat Teams are finally getting a much-requested Mobile Protected Firepower platform a light tank with a 105 mm gun. This is almost exactly the same in concept to the M18 Hellcat.

        We’re not done on this topic yet. I am aiming to publish a follow-up to Rexer’s article: The Tank Destroyer Rides Again!


      4. For this the reason being that there aren’t many mountain tanks around: ” M-18 was subsequently adopted by the Yugoslavian Army and remained in service until 1990. ” Austria produced what I think was called Kuirassier and that sold to the Andies countries (then). India has been in the market to buy 300 modern mountain tanks, to match the Chinese… but there aren’t any to buy. Getting interesting from that point of view, with the incursion in the Leh region.


  9. As for ” After the war, Britain too standardised around a single tank, the Centurion. ” you are forgetting that they were slow in coming to service and the same gun was put onto an older tank chassis: enter The Charioteer!

    Liked by 3 people

  10. For the follow-on “The Tank Destroyer Rides Again! ” these couple of comments might be out of scope, so will speculate here:
    Stalingrad gave rise to some engineering -type assault guns, like damaged Tigers being rebuilt with a “gun” borrowed from the navy and meant for ships engaging fortifications. Modern ABVs (for breaching defences more generally) are in the line-up of US and Russian forces – but rare elsewhere
    – hard to understand against the background of everyone saying that urban combat is becoming the ‘norm’

    If you send vehicles like that in, then they will most likely be engaged from above (buildings) and escorting tanks are quite limited in their gun elevation. The IDF Carmel (concept) would seem to rectify this
    – 57 mm coming back was already touched on (Russian initiatives)
    – will the IMI 60 mm gun that creates more pressure on target than the rather punchy Bofors 40 make a come back, for punching holes in structures? The Bofors with its long barrel is unpractical in some urban situations and for the CTA, which has less of that problem, I don’t have the stats – but is said to be roughly on par with the Bofors

    Liked by 1 person

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