Ordnance QF 6-pounder

The Ordnance Quick-Firing 6-pounder 7 cwt, or just 6 pounder, was a British 57 mm gun, their primary anti-tank gun during the middle of World War II, as well as the main armament for a number of armoured fighting vehicles. It was first used in North Africa in April 1942, and quickly replaced the 2 pounder in the anti-tank role, allowing the 25 pounder to revert to its intended artillery role. The United States Army also adopted the 6 pdr as their primary anti-tank gun under the designation 57 mm Gun M1.

Country Name Origin Year
United Kingdom - UK (Great Britain) 1942
Country Name Operational Year Retirement Year
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Russia (USSR) View
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United Kingdom - UK (Great Britain) 1942 1960 View
United States of America View

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 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 from the 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. The loss of equipment - most of the BEF's heavy equipment had to be left behind in France during Operation Dynamo - and the prospect of a German 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. It was estimated that 100 6-pounders would displace the production of 600 2-pounders. 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. Optional side shields were issued to give the crew better protection, but were apparently rarely used.

The 6 pounder was used where possible to replace the 2-pounder in current British tanks, requiring work on the turrets, pending the introduction of new tanks designed to take the 6-pounder from the outset. The Churchill Marks III and IV, Valentine Mark IX and Crusader Mark III all began to enter service during 1942. The Valentine and Crusader both needed to lose a crew member from the turret. Those tanks designed to take the 6-pounder from the outset were the problematic Cavalier and the Cromwell and Centaur. When the Cromwell went into combat in 1944 it was however armed with the Ordnance QF 75 mm gun, which was a redesign of the 6-pounder to take US 75 mm ammunition and more useful against general targets. The 6-pounder was also fitted to the AEC Armoured Car Mark II.

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 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 not only for the rest of World War II, but also for some 20 years after the war.

A 57/42.6 mm squeeze bore adaptor was developed for the gun but was never adopted.

In addition to the UK, the gun was produced in Canada.

The Combined Ordnance Factories (COFAC) of South Africa produced three hundred examples as well.

Type Anti-tank gun
Tank gun
Place of origin United Kingdom
Service history
In service 1942–1960
Used by British Empire
United States
South Korea
Wars World War II
Korean War
1956 Suez War
Production history
Designed 1940
Produced 1941–1945
Weight 2,520 lb (1,140 kg)
Barrel length Mk II, III: 8 ft 4 in (2.54 m) 43 calibres
Mk IV, V and M1: 50 calibres
Crew 6
Shell 57×441 mm. R
Calibre 2.24 in (57 mm)
Breech vertical sliding block
Carriage split trail
Elevation -5° to +15°
Traverse 90°
Muzzle velocity See ammunition table
Effective firing range 1,650 yd (1,510 m)
Maximum firing range 5,000 yd (4,600 m)
Sights No.22c

End notes