Ordnance QF 6-pounder

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Ordnance QF 6-pounder 7 cwt
QF 6 pdr at Batey ha-Osef
TypeAnti-tank gun
Place of origin United Kingdom
Service history
In service1942–1960
Used byBritish Commonwealth, United States
WarsWW2
Production history
Designed1940
Produced1941–1945
Specifications
Mass1,140 kg / 2,520 lb
Length2.82 m
Barrel lengthMk II, III: 43 calibres
Mk IV, V and M1: 50 calibres
Crew6

Shell57×441mmR
Calibre2.24 in (57 mm)
Breechvertical block
Carriagesplit trail
Elevation15 degrees
Traverse90 degrees
Maximum firing range5,000 yards (4,600 m)
SightsNo.22c
QF 6 pounder anti-tank gun in Batey ha-Osef museum, Israel.

The Ordnance QF 6-pounder 7 cwt, or just 6 pdr, 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 57mm Gun M1.

Development and production

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 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 late 19th century, and therefore manufacturing equipment was available. The design was complete by 1940, but the carriage design was not completed until 1941. [citation needed] The production was further delayed by the defeat in the Battle of France. The loss of equipment 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. 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 shorter L/43* barrel, because of shortage in suitable lathes. The subsequent Mk IV was fitted with L/50 barrel with muzzle brake. Optional side shields were issued to give the crew better protection, but were apparently rarely used. *The L/43 refers to the barrel length in multiples of the calibre - therefore the barrel length would be 43 x 57 = 2451 mm.

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 pdr of 59 calibre length, but this version proved too heavy to be used in the same role as the 6 pdr. 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 the 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 Ordinance Factories (COFAC) of South Africa 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 in February 1941. At that time the U.S. Army still favoured the 37mm Gun M3 and production was planned solely for lend lease. The U.S. version, classified as substitute standard under the designation 57mm Gun M1, was based on the 6 pounder Mk 2, two units of which were received from the UK, but unlike the Mk II had the original long barrel. Production started early in 1942 and continued until 1945.

М1 production, pcs.
Year 1942 1943 1944 1945 Total
Produced, pcs. 3,877 5,856 3,902 2,002 15,637

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

Service history

A 6-pdr anti-tank gun and its crew in action in the Western Desert, 3 November 1942

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 anti-tank regiments of infantry and armoured divisions in the western theatres (four batteries with 12 pieces each), and later in the war to the six-gun anti-tank platoons of infantry battalions. An airlanding battalion had an AA/AT company, with two four-gun AT platoons. The Far East theatres had lower priority and different organization, reflecting lower tank threat. The gun was also employed by Commonwealth forces, in formations similar to the British ones.

Initially the anti-tank ammunition was represented by a basic Armour-Piercing (AP) shot, but by January 1943 an Armour-Piercing, Capped (APC) shot and an Armour-Piercing, Capped, Ballistically Capped (APCBC) shots were 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. 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 Rifle Brigade (together with part of 239 Anti-Tank Battery Royal Artillery under command), destroyed more than 30 enemy tanks in the action at 'Snipe' during the battle of Alamein. However, over the next year the Germans introduced much heavier designs into service, notably the Tiger I and Panther. The standard 6 pounder shot was only effective frontally at short ranges and shallow angles against the front armour of these new designs (and only the turret of the Panther), but it was still effective against them from other angles. In fact, it was the 6-pounder gun that accounted for the first Tiger destroyed in North Africa (and the Churchill tank was the first western tank to knock out the Tiger I in tank v 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 1960, when it was finally declared obsolete.

U.S. service

57 mm Gun M1 firing at German bunker near Saint-Malo, Brittany.

In spring 1943, following the experience of the North African Campaign, 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 (TO&E) from 26 May 1943, a regimental antitank company included nine 57 mm guns and each battalion had an antitank platoon with three guns giving a total of 18 guns per regiment. Dodge WC-62 / WC-63 6x6 1 1/2 ton trucks were issued as prime movers. By mid-1944 the M1 was the standard antitank gun of the U.S. infantry in the Western Front and outnumbered the M3 in Italy.

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 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.

The Airborne Command had rejected the 57 mm M1 in the summer of 1943 claiming its unfitness for airlifting and the TO&E of February 1944 still had airborne divisions keeping their 37 mm guns. Nevertheless, the 82nd and the 101st airborne divisions were reequipped with British-manufactured 6 pounders on carriage Mk 3 (24 in AA battalion, and 9 in glider infantry 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.

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 (653), USSR (400) and Brazil (57).

Israel employed the 6-pounder in 1950s in brigade-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 in 1956, too late to enter service before the Suez Crisis. 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 Pakistan Army; numerous examples can still be seen as 'gate guards' outside army bases in Pakistan.

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.

Variants

External images
image icon Sketch of the 6-pounder Mk 2. [1]
image icon 6-pounder Mk IV in action in Normandy. [2]
image icon 57 mm M1 of the 44th Infantry Division in France, 1944. [3]
image icon M1 in a street of Rimschweiler, Germany. [4]
image icon 57 mm GMC T49. [5]
  • 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 vending machines. It was mounted on the Royal Navy Motor Torpedo Boats, a limited number of Royal Navy Escort Destroyers ("V and W" class vessels in a twin mounting at "A" gun position) and in the RAF Mosquito planes, which were then referred to as the "Tsetse".
  • 57mm 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
A T48 57 mm Gun Motor Carriage in front of the Polish Army Museum.

Self-propelled mounts

Tank gun versions of the 6-pounder were used in Crusader III, Cavalier, Centaur I and II, Cromwell I to III, Valentine VIII to X and Churchill III and IV, and also in the Canadian Ram Mk II and the experimental American Light Tank T7E2. The Deacon and the experimental Alecto Mk II 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.

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, was stopped after 30 units were built. A project of tank destroyer armed with the M1—the 57mm Gun Motor Carriage T49—was cancelled after a single pilot vehicle was built. Similarly, the wheeled 57mm Gun Motor Carriage T44, based on Ford 4x4 3/4 ton cargo carrier chassis, was cancelled after a brief testing.

Ammunition

Available ammunition
Type Model Weight, kg 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 - 853 892
APC (from September 1942) Shot, APC, Mk 8T 2.86 - 846 884
APCBC (from January 1943) Shot, APCBC, Mk 9T 3.23 - 792 831
APCR (from October 1943) Shot, APCR, Mk 1T 1.90 - 1,082
APDS (from March 1944) Shot, APDS, Mk 1T 1.42 - 1,219
HE Shell, HE, Mk 10T approx. 3 820
U.S. ammunition
AP AP Shot M70 2.85 - 853
APCBC/HE APC Shot M86 3.30 Dunnite, 34 g 823
HE (authorized in March 1944) HE Shell T18 / M303
Canister (in production from January 1945) Canister Shot T17 / M305

See also

References

  • Chamberlain, Peter (1974). Anti-Tank Weapons. WWII Fact Files. Arco Publishing Company, New York. ISBN 0-668-03505-6. {{cite book}}: Unknown parameter |coauthors= ignored (|author= suggested) (help)
  • Hogg, Ian V. (1998). Allied Artillery of World War Two. Crowood Press, Ramsbury. ISBN 1-86126-165-9. {{cite book}}: Cite has empty unknown parameter: |coauthors= (help)
  • Hunnicutt, R. P. (1992). Stuart: A History of the American Light Tank. Presidio Press. ISBN 0-89141-462-2. {{cite book}}: Cite has empty unknown parameter: |coauthors= (help)
  • Hunnicutt, R. P. (2002). Armored Car: A History of American Wheeled Combat Vehicles. Presidio Press. ISBN 0-89141-777-X. {{cite book}}: Cite has empty unknown parameter: |coauthors= (help)
  • When the Engines Roared: 50th Anniversary to the Sinai War (ברעום המנועים: 50 שנה למלחמת סיני ). Ministry of Defence, Israel. 2006. ISBN 965-05-1337-X. {{cite book}}: Cite has empty unknown parameter: |coauthors= (help)
  • Zaloga, Steven J. (2005). US Anti-tank Artillery 1941-45. New Vanguard 107. illustrated by Brian Delf. Osprey Publishing. ISBN 1-84176-690-9. {{cite book}}: Cite has empty unknown parameter: |coauthors= (help)
  • Zaloga, Steven J. (2007). US Airborne Divisions in the ETO 1944-45. Battle Orders 25. Osprey Publishing. ISBN 1-84176-118-2. {{cite book}}: Check |isbn= value: checksum (help); Cite has empty unknown parameter: |coauthors= (help)

External links