Ordnance QF 6 pounder
Overview
 
The Ordnance Quick-Firing 6-pounder 7 cwt, or just 6 pounder, was a British
United Kingdom
The United Kingdom of Great Britain and Northern IrelandIn the United Kingdom and Dependencies, other languages have been officially recognised as legitimate autochthonous languages under the European Charter for Regional or Minority Languages...

 57 mm gun, their primary anti-tank gun during the middle of World War II
World War II
World War II, or the Second World War , was a global conflict lasting from 1939 to 1945, involving most of the world's nations—including all of the great powers—eventually forming two opposing military alliances: the Allies and the Axis...

, as well as the main armament for a number of armoured fighting vehicle
Armoured fighting vehicle
An armoured fighting vehicle is a combat vehicle, protected by strong armour and armed with weapons. AFVs can be wheeled or tracked....

s. It was first used in North Africa
North African campaign
During the Second World War, the North African Campaign took place in North Africa from 10 June 1940 to 13 May 1943. It included campaigns fought in the Libyan and Egyptian deserts and in Morocco and Algeria and Tunisia .The campaign was fought between the Allies and Axis powers, many of whom had...

 in April 1942, and quickly replaced the 2 pounder
Ordnance QF 2 pounder
The Ordnance QF 2-pounder was a British anti-tank and vehicle-mounted gun, employed in the Second World War. It was actively used in the Battle of France, and during the North Africa campaign...

 in the anti-tank role, allowing the 25 pounder to revert to its intended artillery role. The United States Army
United States Army
The United States Army is the main branch of the United States Armed Forces responsible for land-based military operations. It is the largest and oldest established branch of the U.S. military, and is one of seven U.S. uniformed services...

 also adopted the 6 pdr as their primary anti-tank gun under the designation 57 mm Gun M1.
Limitations of the existing 2 pounders were apparent even as the gun was first entering service, and an effort was made to replace it with a much more capable weapon starting as early as 1938.
Encyclopedia
The Ordnance Quick-Firing 6-pounder 7 cwt, or just 6 pounder, was a British
United Kingdom
The United Kingdom of Great Britain and Northern IrelandIn the United Kingdom and Dependencies, other languages have been officially recognised as legitimate autochthonous languages under the European Charter for Regional or Minority Languages...

 57 mm gun, their primary anti-tank gun during the middle of World War II
World War II
World War II, or the Second World War , was a global conflict lasting from 1939 to 1945, involving most of the world's nations—including all of the great powers—eventually forming two opposing military alliances: the Allies and the Axis...

, as well as the main armament for a number of armoured fighting vehicle
Armoured fighting vehicle
An armoured fighting vehicle is a combat vehicle, protected by strong armour and armed with weapons. AFVs can be wheeled or tracked....

s. It was first used in North Africa
North African campaign
During the Second World War, the North African Campaign took place in North Africa from 10 June 1940 to 13 May 1943. It included campaigns fought in the Libyan and Egyptian deserts and in Morocco and Algeria and Tunisia .The campaign was fought between the Allies and Axis powers, many of whom had...

 in April 1942, and quickly replaced the 2 pounder
Ordnance QF 2 pounder
The Ordnance QF 2-pounder was a British anti-tank and vehicle-mounted gun, employed in the Second World War. It was actively used in the Battle of France, and during the North Africa campaign...

 in the anti-tank role, allowing the 25 pounder to revert to its intended artillery role. The United States Army
United States Army
The United States Army is the main branch of the United States Armed Forces responsible for land-based military operations. It is the largest and oldest established branch of the U.S. military, and is one of seven U.S. uniformed services...

 also adopted the 6 pdr as their primary anti-tank gun under the designation 57 mm Gun M1.

Development

Limitations of the existing 2 pounders were apparent even as the gun was first entering service, and an effort was made to replace it with a much more capable weapon starting as early as 1938. The Woolwich Arsenal
Royal Arsenal
The Royal Arsenal, Woolwich, originally known as the Woolwich Warren, carried out armaments manufacture, ammunition proofing and explosives research for the British armed forces. It was sited on the south bank of the River Thames in Woolwich in south-east London, England.-Early history:The Warren...

 was entrusted with the development. The 57 mm calibre was chosen for the new gun. Guns of this calibre were employed by the Royal Navy
Royal Navy
The Royal Navy is the naval warfare service branch of the British Armed Forces. Founded in the 16th century, it is the oldest service branch and is known as the Senior Service...

 from late 19th century, and therefore manufacturing equipment was available. The design was complete by 1940, but the carriage design was not completed until 1941. The production was further delayed by the defeat in the Battle of France
Battle of France
In the Second World War, the Battle of France was the German invasion of France and the Low Countries, beginning on 10 May 1940, which ended the Phoney War. The battle consisted of two main operations. In the first, Fall Gelb , German armoured units pushed through the Ardennes, to cut off and...

. The loss of equipment and the prospect of a German
Nazi Germany
Nazi Germany , also known as the Third Reich , but officially called German Reich from 1933 to 1943 and Greater German Reich from 26 June 1943 onward, is the name commonly used to refer to the state of Germany from 1933 to 1945, when it was a totalitarian dictatorship ruled by...

 invasion made re-equipping the army with anti-tank weapons an urgent task, so a decision was made to carry on the production of the 2 pounder, avoiding the period of adaptation to production, and also of re-training and acclimatization with the new weapon. This had the effect of delaying production of the 6 pounder until November 1941 and its entry into service until May 1942.

Unlike the 2-pounder, the new gun was mounted on a conventional two-wheeled split trail carriage. The first mass production variant—the Mk II—differed from the pre-production Mk I in having a shorter L/43 barrel, because of shortage of suitable lathes. The subsequent Mk IV was fitted with a L/50 barrel, with muzzle brake
Muzzle brake
Muzzle brakes and recoil compensators are devices that are fitted to the muzzle of a firearm or cannon to redirect propellant gases with the effect of countering both recoil of the gun and unwanted rising of the barrel during rapid fire...

. Optional side shields were issued to give the crew better protection, but were apparently rarely used.

Although the 6 pounder was kept at least somewhat competitive through the war, the Army nevertheless started development of a more powerful weapon in 1942. Their aim was to produce a gun with the same general dimensions and weight as the 6 pounder, but with improved performance. The first attempt was an 8 pounder of 59 calibre length, but this version proved too heavy to be used in the same role as the 6 pounder. A second attempt was made with a shorter 48 calibre barrel, but this proved to have only marginally better performance than the 6 pounder. The program was eventually cancelled in January 1943.

Instead the 6 pounder was followed into production and service by the next generation British anti-tank gun, the 17 pounder
Ordnance QF 17 pounder
The Ordnance Quick-Firing 17 pounder was a 76.2 mm gun developed by the United Kingdom during World War II. It was used as an anti-tank gun on its own carriage, as well as equipping a number of British tanks. It was the most effective Allied anti-tank gun of the war...

 which came into use from February 1943. As a smaller and more manoeuvrable gun, the 6 pounder continued to be used by the British Army
British Army
The British Army is the land warfare branch of Her Majesty's Armed Forces in the United Kingdom. It came into being with the unification of the Kingdom of England and Scotland into the Kingdom of Great Britain in 1707. The new British Army incorporated Regiments that had already existed in England...

 not only for the rest of the World War II
World War II
World War II, or the Second World War , was a global conflict lasting from 1939 to 1945, involving most of the world's nations—including all of the great powers—eventually forming two opposing military alliances: the Allies and the Axis...

, but also for some 20 years after the war.

A 57/42.6 mm squeeze bore
Littlejohn adaptor
The Littlejohn adaptor was a device that could be added to the British QF 2 pounder anti-tank gun. It was used to extend the service life of the 2-pounder during the Second World War by converting it to squeeze bore operation...

 adaptor was developed for the gun but was never adopted.

In addition to the UK, the gun was produced in Canada
Canada
Canada is a North American country consisting of ten provinces and three territories. Located in the northern part of the continent, it extends from the Atlantic Ocean in the east to the Pacific Ocean in the west, and northward into the Arctic Ocean...

.

The Combined Ordinance Factories (COFAC) of South Africa
South Africa
The Republic of South Africa is a country in southern Africa. Located at the southern tip of Africa, it is divided into nine provinces, with of coastline on the Atlantic and Indian oceans...

 produced three hundred examples as well.

U.S. production

The idea of manufacturing the 6 pounder in the U.S. was expressed by the U.S. Army Ordnance
Ordnance Corps
The United States Army Ordnance Corps is a Sustainment branch of the United States Army, headquartered at Fort Lee, Virginia.-Mission Statement:The U.S...

 in February 1941. At that time the U.S. Army still favored the 37mm Gun M3 and production was planned solely for lend lease. The U.S. version, classified as substitute standard under the designation 57 mm Gun M1, was based on the 6 pounder Mk 2, two units of which were received from the UK. However since there was sufficient lathe capacity the longer barrel could be produced from the start. Production started early in 1942 and continued until 1945. The M1A1 variant used US "Combat" tyres and wheels. The M1A2 introduced the British practice of free traverse, i.e., the gun could be traversed by the crew pushing and pulling on the breech, instead of solely geared traverse, from September 1942.
A more stable carriage was developed but not introduced. Once the 57 mm did enter US service a modified towing point design was introduced (the M1A3) but only for US use.
М1 production
Year 1942 1943 1944 1945 Total
Number produced 3,877 5,856 3,902 2,002 15,637


About one-third of production was delivered to the UK.

Like the British Army, the U.S. Army also experimented with a squeeze bore adaptor (57/40 mm T10), but the program was abandoned.

American shell designs and production lagged behind the introduction of the gun once it was accepted for service and so at first only AP shot was available.
The HE shell was not available until after the Normandy landings and UK stocks were procured to cover its absence.

Service history

British service

The 6-pounders (and the U.S.-built M1, of which 4,242 pieces were received) were initially issued to the Royal Artillery
Royal Artillery
The Royal Regiment of Artillery, commonly referred to as the Royal Artillery , is the artillery arm of the British Army. Despite its name, it comprises a number of regiments.-History:...

 anti-tank regiment
Regiment
A regiment is a major tactical military unit, composed of variable numbers of batteries, squadrons or battalions, commanded by a colonel or lieutenant colonel...

s of infantry and armoured divisions
Division (military)
A division is a large military unit or formation usually consisting of between 10,000 and 20,000 soldiers. In most armies, a division is composed of several regiments or brigades, and in turn several divisions typically make up a corps...

 in the western theatres (four batteries
Artillery battery
In military organizations, an artillery battery is a unit of guns, mortars, rockets or missiles so grouped in order to facilitate better battlefield communication and command and control, as well as to provide dispersion for its constituent gunnery crews and their systems...

 with 12 pieces each), and later in the war to the six-gun anti-tank platoon
Platoon
A platoon is a military unit typically composed of two to four sections or squads and containing 16 to 50 soldiers. Platoons are organized into a company, which typically consists of three, four or five platoons. A platoon is typically the smallest military unit led by a commissioned officer—the...

s of infantry battalion
Battalion
A battalion is a military unit of around 300–1,200 soldiers usually consisting of between two and seven companies and typically commanded by either a Lieutenant Colonel or a Colonel...

s. An airlanding battalion had an AA/AT company, with two four-gun AT platoons. The Far East
Far East
The Far East is an English term mostly describing East Asia and Southeast Asia, with South Asia sometimes also included for economic and cultural reasons.The term came into use in European geopolitical discourse in the 19th century,...

 theatres had lower priority and different organization, reflecting lower tank threat. The gun was also employed by Commonwealth
Commonwealth of Nations
The Commonwealth of Nations, normally referred to as the Commonwealth and formerly known as the British Commonwealth, is an intergovernmental organisation of fifty-four independent member states...

 forces, in formations similar to the British ones.

Initially the anti-tank ammunition was a basic Armour-Piercing (AP) shot, but by January 1943 an Armour-Piercing, Capped (APC) shot and an Armour-Piercing, Capped, Ballistically Capped (APCBC) shot was supplied. A HE shell was produced so that the gun could be used against unarmoured targets as well.

The 6-pounder first saw action in May 1942 at Gazala
Battle of Gazala
The Battle of Gazala was an important battle of the Second World War Western Desert Campaign, fought around the port of Tobruk in Libya from 26 May-21 June 1942...

. It made an immediate impact on the battlefield as it was able to penetrate any enemy tank then in service. In the most celebrated action, the 6-pounder guns of 2nd Battalion, The Rifle Brigade (together with part of 239 Anti-Tank Battery Royal Artillery under command), destroyed more than 15 enemy tanks in the action at 'Snipe'
Outpost Snipe
Outpost Snipe was the location of a famous Second World War defensive action during the desert campaign in Egypt. The defense of Outpost Snipe took place during the Second Battle of El Alamein...

 during the battle of Alamein
Alamein
Alamein can refer to:*El Alamein, a town in Egypt*First and Second Battle of El Alamein, during World War II*Alamein railway line, Melbourne, Australia**Alamein railway station on the line*HMS Alamein, a destroyer of the Royal Navy...

. However, over the next year the Germans introduced much heavier designs into service, notably the Tiger I
Tiger I
Tiger I is the common name of a German heavy tank developed in 1942 and used in World War II. The final official German designation was Panzerkampfwagen Tiger Ausf. E, often shortened to Tiger. It was an answer to the unexpectedly formidable Soviet armour encountered in the initial months of...

 and Panther
Panther tank
Panther is the common name of a medium tank fielded by Nazi Germany in World War II that served from mid-1943 to the end of the European war in 1945. It was intended as a counter to the T-34, and to replace the Panzer III and Panzer IV; while never replacing the latter, it served alongside it as...

. The standard 6 pounder shot was effective frontally at short ranges as shown in the Armour plate experiment, but proved ineffective at extended ranges. It was the 6-pounder gun that accounted for the first Tiger destroyed in North Africa when mounted in the Churchill tank
Churchill tank
The Tank, Infantry, Mk IV was a heavy British infantry tank used in the Second World War, best known for its heavy armour, large longitudinal chassis with all-around tracks with multiple bogies, and its use as the basis of many specialist vehicles. It was one of the heaviest Allied tanks of the war...

 (which was the first western tank to knock out the Tiger I in tank vs tank combat).

The situation was somewhat improved by the development of more sophisticated ammunition, in form of the Armour-Piercing, Composite Rigid (APCR) shot, and the Armour-Piercing, Discarding Sabot (APDS) shot, which was available from 1944.

In the Royal Artillery regiments the 6-pounders were joined by the 17-pounders starting in 1943, but in infantry units the gun remained the sole AT gun in service until 1951, when it was finally declared obsolete and replaced with the 17-pounders in BAOR ( British Army of the Rhine).

U.S. service

In spring 1943, following the experience of the North African Campaign
North African campaign
During the Second World War, the North African Campaign took place in North Africa from 10 June 1940 to 13 May 1943. It included campaigns fought in the Libyan and Egyptian deserts and in Morocco and Algeria and Tunisia .The campaign was fought between the Allies and Axis powers, many of whom had...

, the Infantry branch of the U.S. Army recognized the need to field a heavier antitank gun than the 37 mm M3. According to the Table of Organization and Equipment
Table of Organization and Equipment
A table of organization and equipment is a document published by the U.S. Department of Defense which prescribes the organization, staffing, and equippage of units. Also used in acronyms as 'T/O' and 'T/E'....

 (TO&E) from 26 May 1943, a regiment
Regiment
A regiment is a major tactical military unit, composed of variable numbers of batteries, squadrons or battalions, commanded by a colonel or lieutenant colonel...

 antitank company included nine 57 mm guns and each battalion
Battalion
A battalion is a military unit of around 300–1,200 soldiers usually consisting of between two and seven companies and typically commanded by either a Lieutenant Colonel or a Colonel...

 had an antitank platoon
Platoon
A platoon is a military unit typically composed of two to four sections or squads and containing 16 to 50 soldiers. Platoons are organized into a company, which typically consists of three, four or five platoons. A platoon is typically the smallest military unit led by a commissioned officer—the...

 with three guns giving a total of 18 guns per regiment. Dodge
Dodge
Dodge is a United States-based brand of automobiles, minivans, and sport utility vehicles, manufactured and marketed by Chrysler Group LLC in more than 60 different countries and territories worldwide....

 WC-62
Dodge WC series
The Dodge WC series was a range of light military trucks produced by Dodge during World War II. The series included weapon carriers, telephone installation trucks, ambulances, reconnaissance vehicles, mobile workshops and command cars. They were replaced after the war by the Dodge M-series...

 / WC-63
Dodge WC series
The Dodge WC series was a range of light military trucks produced by Dodge during World War II. The series included weapon carriers, telephone installation trucks, ambulances, reconnaissance vehicles, mobile workshops and command cars. They were replaced after the war by the Dodge M-series...

 6×6 1½ ton trucks were issued as prime movers
Artillery tractor
Artillery tractor is a kind of tractor, also referred to as a gun tractor, a vehicle used to tow artillery pieces of varying weights.-Traction:...

 in place of the 3/4 ton truck used with its predecessor the 37mm.
Introduction was made in the face of objections by the Infantry Board which believed it too heavy. The Ordnance Board on the other hand felt a more powerful weapon should be introduced. Airborne and Cavalry rejected it.
By mid-1944 the M1 was the standard antitank gun of the U.S. infantry in the Western Front
Western Front (World War II)
The Western Front of the European Theatre of World War II encompassed, Denmark, Norway, Luxembourg, Belgium, the Netherlands, France, and West Germany. The Western Front was marked by two phases of large-scale ground combat operations...

 and outnumbered the M3 in Italy
Italian Campaign (World War II)
The Italian Campaign of World War II was the name of Allied operations in and around Italy, from 1943 to the end of the war in Europe. Joint Allied Forces Headquarters AFHQ was operationally responsible for all Allied land forces in the Mediterranean theatre, and it planned and commanded the...

.

Because of the unexpected adoption for service, the only ammunition type in production in the U.S. by mid-1943 was the AP ammunition. Only after the Normandy Campaign did the HE round reach battlefield (U.S. units were sometimes able to get a limited amount of HE ammunition from the British Army), and the canister shot
Canister shot
Canister shot is a kind of anti-personnel ammunition used in cannons. It was similar to the naval grapeshot, but fired smaller and more numerous balls, which did not have to punch through the wooden hull of a ship...

 was not seen in significant numbers until the end of the war. This limited the efficiency of the gun in the infantry support role. Also, APCR or APDS rounds were never developed. Canister round production did not start until early 1945 and was also in limited use. Some British stocks of APDS were supplied to the US units.

The Airborne Command had rejected the 57 mm M1 in the summer of 1943 claiming its was unfit for airlanding by glider due to weight and the TO&E of February 1944 still had airborne divisions keeping their 37 mm guns. Nevertheless, the 82nd and the 101st
101st Airborne Division (United States)
The 101st Airborne Division—the "Screaming Eagles"—is a U.S. Army modular light infantry division trained for air assault operations. During World War II, it was renowned for its role in Operation Overlord, the D-Day landings on 6 June 1944, in Normandy, France, Operation Market Garden, the...

 airborne divisions were reequipped with British-manufactured 6 pounders on the narrow carriage Mk III designed for glider use - 24 in AA battalion, and 9 in glider infantry
Glider infantry
Glider infantry was a type of airborne infantry in which soldiers and their equipment were inserted into enemy controlled territory via military glider rather than parachute...

 regiment - for the Normandy airdrops. Subsequently the guns were officially introduced under the TO&E from December 1944. According to the TO&E, a division was issued a total of 50 pieces: 8 in divisional artillery, 24 in AA battalion, and 18 in glider infantry regiment; parachute infantry regiments did not have anti-tank guns. The British guns were referred simply as 57 mm guns.

In the fighting after the Normandy landings the paratroops used them against German armour near St Mere Eglise and Carentan. However few tanks were encountered and they were mostly used for support which made the shortage of HE shell more significant. From July, US anti-tank units encountered the Panther tank which was only vulnerable to the 57 mm from the sides. Towed anti-tank guns were less effective in the hedgerow terrain where mobility suffered but when the Germans went on the offensive in August they were effective in defence with infantry. Towards the end of the war, towed anti-tank units were out of favour due to their lack of mobility compared to self-propelled guns and the 57mm was used by infantry battalions. However with few tanks to contend with some units that would have been equipped with the 57mm were instead deployed as rifle companies or only with the Bazooka.

The M1 went out of service in the U.S. soon after the end of the war.

Other operators

In addition to being used by the U.S., British and commonwealth forces, the M1 was supplied under the lend lease program to the Free French Forces
Free French Forces
The Free French Forces were French partisans in World War II who decided to continue fighting against the forces of the Axis powers after the surrender of France and subsequent German occupation and, in the case of Vichy France, collaboration with the Germans.-Definition:In many sources, Free...

 (653), USSR (400) and Brazil
Brazil
Brazil , officially the Federative Republic of Brazil , is the largest country in South America. It is the world's fifth largest country, both by geographical area and by population with over 192 million people...

 (57).

The Royal Navy used the 6-pounder extensively in Motor Gunboats during World War II (especially the 'D' type). The gun was mounted on a hydraulic powered mount and fitted with the Molins power loading system, permitting a 6-round burst at 1 round per second. The guns were all the early short-barrel (43 calibre) type, and fired exclusively HE ammunition, at much lower muzzle velocities than for AP.

The Israel Defense Forces
Israel Defense Forces
The Israel Defense Forces , commonly known in Israel by the Hebrew acronym Tzahal , are the military forces of the State of Israel. They consist of the ground forces, air force and navy. It is the sole military wing of the Israeli security forces, and has no civilian jurisdiction within Israel...

 employed the 6-pounder in 1950s in brigade
Brigade
A brigade is a major tactical military formation that is typically composed of two to five battalions, plus supporting elements depending on the era and nationality of a given army and could be perceived as an enlarged/reinforced regiment...

-level anti-tank battalions and battalion-level anti-tank platoons (the latter formations were disbanded in 1953). By late 1955, Israel Defense Forces possessed 157 pieces and 100 more were purchased from the Netherlands
Netherlands
The Netherlands is a constituent country of the Kingdom of the Netherlands, located mainly in North-West Europe and with several islands in the Caribbean. Mainland Netherlands borders the North Sea to the north and west, Belgium to the south, and Germany to the east, and shares maritime borders...

 in 1956, too late to enter service before the Suez Crisis
Suez Crisis
The Suez Crisis, also referred to as the Tripartite Aggression, Suez War was an offensive war fought by France, the United Kingdom, and Israel against Egypt beginning on 29 October 1956. Less than a day after Israel invaded Egypt, Britain and France issued a joint ultimatum to Egypt and Israel,...

. Some of those are described as "57-mm guns, nearly identical to the 6-pounders and firing the same ammunition", which apparently makes them U.S.-built M1 guns.

The gun was also used by the Pakistani Army; numerous examples can still be seen as 'gate guards' outside army bases in Pakistan.

The Irish Army
Irish Army
The Irish Army, officially named simply the Army is the main branch of the Defence Forces of Ireland. Approximately 8,500 men and women serve in the Irish Army, divided into three infantry Brigades...

 acquired six 6 pounder anti-tank guns in the late 1940s.

Modern day use

The U.S. 57 mm M1 gun is popular with modern-day cannoneers, as there is a relatively good supply of shell casings and projectiles.

The gun is also reportedly still in active military use with some South American countries and, in coastal defense emplacements, outlying island garrisons of the Republic of China Army
Republic of China Army
The ROC Army's current operational strength includes 3 armies, 5 corps. As of 2005, the Army's 35 brigades include 25 infantry brigades, 5 armoured brigades and 3 mechanized infantry brigades...

.

Variants

  • Mk 1: limited production version with L/50 barrel.
  • Mk 2: first mass production version. Shortened L/43 barrel was adopted due to the shortage of suitable manufacturing equipment.
  • Mk 3: tank version of Mk 2.
  • Mk 4: L/50 barrel, single baffle muzzle brake.
  • Mk 5: tank version of Mk 4 .
  • Molins Class M gun: 6 pounder gun fitted with automatic loader built by the Molins company, a manufacturer of cigarette making machines. It was mounted on the Royal Navy Motor Torpedo Boat
    Motor Torpedo Boat
    Motor Torpedo Boat was the name given to fast torpedo boats by the Royal Navy, and the Royal Canadian Navy.The capitalised term is generally used for the Royal Navy boats and abbreviated to "MTB"...

    s and in the RAF
    Royal Air Force
    The Royal Air Force is the aerial warfare service branch of the British Armed Forces. Formed on 1 April 1918, it is the oldest independent air force in the world...

     Mosquito planes, which were referred to as the "Tsetse
    Tsetse fly
    Tsetse , sometimes spelled tzetze and also known as tik-tik flies, are large biting flies that inhabit much of mid-continental Africa between the Sahara and the Kalahari deserts. They live by feeding on the blood of vertebrate animals and are the primary biological vectors of trypanosomes, which...

    ". Reports of use in a limited number of Royal Navy Escort Destroyers ("V and W" class vessels
    V and W class destroyer
    The V and W class was an amalgam of six similar classes of destroyer built for the Royal Navy under the War Emergency Programme of the First World War and generally treated as one class...

    ) in a twin mounting at "A" gun position appear to be confusion with the use of the 6 Pdr 10 Cwt 'Twin Six'
    QF 6 pounder 10 cwt gun
    The British QF 6 pounder 10 cwt gun"6 pounder" refers to approximate weight of projectiles, which was a traditional British way of denoting small guns. "10 cwt" referred to the approximate weight of the gun and breech in cwt rounded up : 10 cwt = 10 x 112 pounds = 1,120 pounds...

     Coastal Gun in that position.
  • 57 mm Gun M1: U.S. built version; although based on Mk II, it had the "original" L/50 barrel.

Carriage types, British:
  • Mk 1
  • Mk 1A: different axle and wheels
  • Mk 2: simplified design
  • Mk 3: modified for use by airborne troops

Carriage types, U.S.:
  • M1
  • M1A1: U.S. wheels and tyres
  • M1A2 (1942): improved traverse mechanism, allowing free traverse
  • M1A3 (1943): modified towing hook; the first version to be adopted by the U.S. Army
  • M2 (1944): caster wheel added to the right trail, relocated trail handles, new utility box
  • M2A1 (1945): improved elevation gear

Self-propelled mounts

Tank gun versions of the 6-pounder were used in Crusader III
Crusader tank
The Tank, Cruiser, Mk VI or A15 Crusader was one of the primary British cruiser tanks of the early part Second World War and perhaps the most important British tank of the North African Campaign...

, Cavalier
Cavalier tank
The Tank, Cruiser, Mk VII Cavalier was an unsuccessful design of British cruiser tank during World War II. It suffered from an underpowered engine, and problems because of the rush to design and build it.- Development :...

, Centaur I and II, Cromwell I to III
Cromwell tank
Tank, Cruiser, Mk VIII, Cromwell ,The designation as the eighth Cruiser tank design, its name given for ease of reference and its General Staff specification number respectively and the related Centaur tank, were one of the most successful series of cruiser tanks fielded by Britain in the Second...

, Valentine VIII to X
Valentine tank
The Tank, Infantry, Mk III, Valentine was an infantry tank produced in the United Kingdom during the Second World War. More than 8,000 of the type were produced in 11 different marks plus various purpose-built variants, accounting for approximately a quarter of wartime British tank production...

 and Churchill III and IV
Churchill tank
The Tank, Infantry, Mk IV was a heavy British infantry tank used in the Second World War, best known for its heavy armour, large longitudinal chassis with all-around tracks with multiple bogies, and its use as the basis of many specialist vehicles. It was one of the heaviest Allied tanks of the war...

, and also in the Canadian Ram Mk II
Ram tank
The Tank Cruiser, Ram was a cruiser tank designed and built by Canada in the Second World War, based on the U.S. M3 Medium tank. Due to the entrance of the United States into the war and the superior design of the American Sherman, it was used exclusively for training purposes and was never used in...

 and the experimental American Light Tank T7E2. The Deacon
Deacon (artillery)
The AEC Mk I Gun Carrier, known as Deacon, was a British armoured fighting vehicle of the Second World War. It was an attempt to make the QF 6 pounder anti-tank gun into a self-propelled artillery piece...

 and the experimental Alecto Mk II
Alecto (SPG)
The Alecto was an experimental self propelled gun developed by the British during the Second World War but terminated with the end of the war in Europe.-Development:...

 self-propelled guns also mounted the 6-pounder. Another experimental vehicle armed with the 6-pounder was a Firefly tank destroyer, based on the Morris Light Reconnaissance Car
Morris Light Reconnaissance Car
Morris Light Reconnaissance Car was a British light armoured car for reconnaisance use produced by the Morris Motor Company and used by the British during the Second World War....

.

The only mass-produced vehicle mounting the 57 mm M1 was the M3 Half-track based 57mm Gun Motor Carriage T48 (also known by its Soviet designation SU-57). The production of the T18E2 armored car, also known as Boarhound
T18 Boarhound
The T18 Boarhound was an American heavy armoured car produced in small numbers for the British Army during the Second World War.-History:In July 1941 the US Army Ordnance Corps issued specifications for a heavy armored car to be built for supply to the British...

, was stopped after 30 units were built. A project of tank destroyer armed with the M1—the 57 mm Gun Motor Carriage T49—was cancelled after a single pilot vehicle was built. Similarly, the wheeled 57 mm Gun Motor Carriage T44, based on Ford 4×4 ¾ ton cargo carrier chassis, was cancelled after a brief testing.

Ammunition

Available ammunition
Type Model Weight
kg (lb)
Filler Muzzle velocity, m/s
(L/43 guns)
Muzzle velocity, m/s
(L/50 guns)
British ammunition
AP Shot, AP, Mks 1 to 7 2.86 (6.3 lb) - 853 892
APC (from September 1942) Shot, APC, Mk 8T 2.86 (6.3 lb) - 846 884
APCBC
APCBC
The armour-piercing capped ballistic cap is a type of armor-piercing shell introduced in the 1930s.-Development:The APCBC munition type was an evolutionary development of the early war armour-piercing capped shell, itself an evolution of the more basic AP and APHE shell types...

 (from January 1943)
Shot, APCBC, Mk 9T 3.23 (7.1 lb) - 792 831
APCR (from October 1943) Shot, APCR, Mk 1T 1.9 (4.2 lb) - 1,082
APDS (from March 1944) Shot, APDS, Mk 1T 1.42 (3.1 lb) - 1,219
HE Shell, HE, Mk 10T approx. 3 (6.6 lb) 820
U.S. ammunition
AP AP Shot M70 2.85 (6.3 lb) - 853
APCBC/HE APC Shot M86 3.3 (7.3 lb) Dunnite
Dunnite
Dunnite, also known as Explosive D or systematically as ammonium picrate, is an explosive developed by Major Dunn in 1906. Ammonium picrate is a salt formed by reacting picric acid and ammonia....

, 34 g
823
HE (authorized in March 1944) HE Shell T18 / M303
Canister
Canister shot
Canister shot is a kind of anti-personnel ammunition used in cannons. It was similar to the naval grapeshot, but fired smaller and more numerous balls, which did not have to punch through the wooden hull of a ship...

 (in production from January 1945)
Canister Shot T17 / M305

See also

  • 6 pounder 6 cwt AA gun
  • 6 pounder 10 cwt
    QF 6 pounder 10 cwt gun
    The British QF 6 pounder 10 cwt gun"6 pounder" refers to approximate weight of projectiles, which was a traditional British way of denoting small guns. "10 cwt" referred to the approximate weight of the gun and breech in cwt rounded up : 10 cwt = 10 x 112 pounds = 1,120 pounds...

     Naval and Coastal defence gun
  • List of U.S. Army weapons by supply catalog designation (SNL C-36)
  • British standard ordnance weights and measurements
    British standard ordnance weights and measurements
    The British standard ordnance weights and measurements for the artillery were established by the Master General of Ordnance in 1764, and these were not altered until 1919 when the metric system was additionally introduced....


External links

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