Ordnance QF 2 pounder

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Ordnance QF 2 pounder
QF 2-pounder anti-tank gun
Type	Anti-tank gun
Place of origin	UK
Service history
In service	1936-1945
Wars	WWII
Production history
Designed	1936
Manufacturer	Vickers
Produced	1936-?
Specifications
Weight	814 kg
Barrel length	overall: 2,081.5 mm / 52 calibers bore: 2,000 mm / 50 calibers

Shell	40x304R
Calibre	40 mm
Breech	semiautomatic vertical block
Recoil	hydrospring
Carriage	three-leg platform
Elevation	-13° to +15°
Traverse:	360°
Rate of fire	22 rounds per minute
Muzzle velocity	792 m/s (2,600 ft/s) with AP shot
Effective range	1,000 yards
Sights	telescopic

The Ordnance QF 2-pounder (or simply "2 pounder gun") was a 40 mm British anti-tank and vehicle-mounted gun, employed in the Second World War. It was actively used in France and during the North African campaign. As tanks became sufficiently armoured to stand up to its shots, it was gradually replaced by the 6-pounder starting in 1942, though some remained in service until the end of the war. In the vehicle-mounted variant, the 2-pounder was also a common fixture on tanks early in World War II and was a typical main armament of medium and heavy armoured cars throughout the war.

1 History
2 Combat Service
3 Ammunition
4 Variants
5 Self-propelled mounts
6 See also
7 Notes
8 References and external links

[edit] History

The gun was initially developed as a tank weapon and made its debut as the main armament of the Vickers-designed Crusier Tank Mk I. For reasons of economy and standardization, in October 1934 the Director of Artillery accepted it as a basis for an anti-tank gun. Contracts to design a carriage were given to Vickers and Woolwich Arsenal.

Vickers was the first to submit a design, which was accepted as Ordnance QF 2-pounder Mark IX on Carriage Mark I and a limited number of pieces were built in 1936. The carriage had an innovative three-legged construction. In the traveling position, one of the legs was used as a towing trail, and the other two were folded. When the gun was positioned for combat, the legs were emplaced on the ground and the wheels were lifted up. When Wollwich Arsenal completed its carriage, it was found to be cheaper and easier to produce than the Vickers design and was therefore adopted as Ordnance QF 2-pounder Mark IX on Carriage Mark II. It followed the same concept lines, although when the gun was emplaced for combat the wheels had to be removed. This variant too was manufactured by Vickers.

The unusual construction gave the gun good stability and a traverse of 360 degrees, allowing it to engage moving vehicles from any approach quickly. The gun could also be fired from wheels, though at the expence of limited traverese. Thanks to slightly larger calibre and larger cartridge it could outperform a typical 37 mm piece such as the German 3.7 cm PaK 36 or the Bofors 37 mm, let alone smaller 25 mm and 20 mm weapons used by some forces. On a negative side, the 2-pounder was nearly twice as heavy as PaK 36 and had higher profile.

One interesting late-war project was the David High Velocity, a Canadian development that allowed 2-pdr ammunition to be fired from the 6-pdr. The idea was to improve the muzzle velocity of the shot. The system was still being developed when the war ended, the program ending along with it.

[edit] Combat Service

The QF 2-punder in Batey ha-Osef Museum, Israel. Note the folded legs of the carriage.

The QF 2-punder in Australian War Memorial.

In the early western campaigns the 2-pds were employed by two types of Royal Artillery formations: anti-tank regiments of infantry divisions (four batteries with 12 pieces each), and light anti-aircraft/anti-tank regiments of armoured divisions (two 12-gun AT batteries). From October 1940, separate 48-gun anti-tank regiments were introduced in armoured divisions too. Infantry brigade structure initially included an anti-tank company, though it was typically equipped with 25 mm Hotchkiss anti-tank guns; these companies were disbanded later in the war. From 1942, infantry battalions received their own six-gun anti-tank platoons. The organization was different in the Far East theatres. The exact internal structure of AT units was also subject to changes and variations.

The gun first saw combat during the German invasion of the Low Countries, with the Belgian Army, and then with the British Army during the subsequent rear-guard actions at Dunkirk. Most of the British Army's 2-pdrs were left behind in France during the retreat, stripping most of the army's infantry anti-tank capability. Those guns captured at Dunkirk entered German service under the designation 4.0 cm Pak 192 (e) or 4.0 cm Pak 154 (b), the "e" and "b" referring to England and Belgium respectively.

Although the Woolwich Arsenal had already designed a successor to the 2-pdr, the 6 pounder gun, it was decided in the face of a likely German invasion to re-equip the army with the 2-pdr, 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 it was only in spring 1942 when the new gun reached frontline units. As such, for most of the North African campaign, the army still had to rely on the 2-pdr, aided by the 25 pounder gun-howitzer functioning as an anti-tank gun - a role for which it was capable though at the expense of taking it away from its main artillery role. The evolution of German tank design meant anti-armour performance of the 2-pdr gradually became insufficient, however the gun owes large part of the bad reputation it gained during the campaign to the open terrain (which made the high-silhouette piece hard to conceal) and to less than perfect tactics.

From mid-1942, the 2-pdr was increasingly displaced to infantry anti-tank platoons, to the Home Guard units in Great Britain and to the Far East, where it was still effective against the considerably less capable Japanese tanks. It was finally removed from service entirely in December 1945. As a vehicle weapon it remained in use throughout the war. Although most tanks models equipped with it were withdrawn or upgraded to the 6-pdr, it remained in use with armoured cars.

Its performance as an anti-armour weapon was improved later in the war with the development of more sophisticated ammunition and got an additional boost with the introduction of the Littlejohn adaptor, which converted it to squeeze-bore design firing specially-designed shells at much higher velocities. These improvements, however, were constantly outpaced by improvements in tank design.

The guns were never equipped with High Explosive rounds which would have given the gun some capability against un-armoured targets, although the rounds had been produced. The shells were not introduced, however, because it was felt that the tiny amount of explosive contained in such a relatively small shell would be ineffective. This proved to be a problem in combat when duels would break out between opposing anti-tank gun units. It also presented a major problem for armoured vehicles equipped with the gun, which were equally limited in dealing with opposing anti-tank guns (and their crews) at distances beyond the range of their machine gun.

[edit] Ammunition

Available ammunition^[1]^[2]
Type	Model	Weight, kg (round/projectile)	Filler	Muzzle velocity, m/s
AP-T	AP/T Mk I Shot	2.04 / 1.08	-	792
AP-T	APHV/T Shot	2.04 / 1.08	-	853
APCBC-T	APCBC/T Mk I Shot	2.22 / 1.22	-	792
APCNR (used with the Littlejohn adaptor)	AP/CNR (APSV) Mk I Shot	? / 0.57	-	1,280
APCNR (used with the Littlejohn adaptor)	AP/CNR (APSV) Mk II Shot	? / 0.45	-	1,189
HE-T	HE/T Mk II Shell	1.86 / 0.86	?	792

Armor penetration table^[2]
Distance, m	91	457	914	1,371
AP (meet angle 60°)	55	47	37	27
APHV (meet angle 60°)		57	45
APCBC (meet angle 60°)		57.5
Different methods of armor penetration measurement were used in different countries / periods. Therefore, direct comparison is often impossible.

[edit] Variants

Gun variants:

Mk IX - main pre-war production version, with barrel of autofrettage construction.
Mk IX-A - Mk IX simplified for mass production.
Mk X - later production version, with forged barrel.
Mk X-A - Mk X with dimension tolerances reduced.
Mk X-B - main late-war vehicle version, fitted with the Littlejohn adaptor.

Carriage variants: