 |
 |
 |
 |
| Ammunition development can be well illustrated with the improvement of the 17-pounder projectile performance. A.P.D.S. shot weighed 3.46kg as opposed to 7.68kg of the standard A.P. shot, and achieved a muzzle velocity of 1,203m/sec (884m/sec for A.P.). The first "Armour-Piercing" (A.P.) shot designed for this gun could pierce 109mm of armour at 914 metres, while an Armour-Piercing Discarding Sabot (A.P.D.S.) shot, arriving to the front line since August 1944, could break into 231mm of armour at the same range, which made the gun a tank killer superior to any other of the world's anti-tank guns of comparable calibre. Nevertheless, other specifications were not so positive. The gun, when it received the split trail carriage designed specifically for this weapon and massive gunshields, weighed 3,040kg, which was more than the German PAK 40 (1,425kg) and the Soviet 76mm Divisional Gun M1942 (1,150kg) put together. When the superb performance of the new gun was proved in combat, new ideas appeared making use of the 17-pounder as a weapon for armoured anti-tank vehicles. The British introduced two designs into service. One was the Archer self-propelled 17-pounder, based on a Valentine chassis with the gun mounted in an open-top body facing back over the engine. Its convenient low profile and thus the possibility of its easy concealment kept it in service until late 1940's. The other design was the Challenger (see a separate article on this vehicle here), based on a longer and wider Cromwell (see a separate article on this vehicle here) chassis, but the design proved much less practical - it was a slow and clumsy vehicle with a huge square turret, making it an easy target for enemy tank killers and artillery. Two other designs, based on American chassis, were much more successful. The first was the American M10 destroyer, issued to the British with a 3in gun. Early in 1943, this gun was removed and a 17-pounder was fitted instead. This proved very much efficient and the tank then became known as "Achilles". Another design was based on the American M4 Sherman tank, refitted with a 17-pounder and known as Sherman Firefly. This became a great success and the Firefly became a feared anti-tank weapon. |
| Facing a steady development of German tank design, the British soon found out that their 2-pounder cannot avoid being out-matched fairly soon. A 57mm 6-pounder design was rediscovered at that time, although it did appear already in 1938. It could not enter production, though, still fully employed with re-supplying the artillery units with 2-pounders. 509 of the army's 676 2-pounders had to be left behind in the Operation Dynamo and the re-armament of the artillery with these guns was preferred to their equipment with a new and unfamiliar gun. Yet in June 1940 first 400 were ordered and before May 1942, some 50 6-pounders a day were leaving British factories. While the 2-pounder gun could pierce 42mm of armour at a range of 914 metres (1,000 yards), the standard steel shot of the 6-pounder could defeat as much as 74mm of armour at the same range. It was actually this weapon which claimed the first Tiger kill in the north African campaign and with the development of special armour piercing ammunition, the gun could get through 127mm of armour in 1944. Like the 2-pounder, besides being a widely used anti-tank artillery weapon, it was also used as a standard tank gun in Crusader Mk. III, Churchill variants Mark III and IV. In November 1940, a year before first 6-pounders were produced, their supreme successor entered its design stage. A 76mm gun firing a 7.7kg (or 17-pound) shot was chosen and in May 1942 the gun was approved for service after several months of testing of the four pilot models. It was high time that such a gun should arrive to the front line units, as the first rumours were arriving of a new generation of German armour, the much acclaimed Tiger tank. Some of the first 17-pounders even had to be mounted onto 25-pounder carriages and rushed to the front line (code-named Pheasant), where the advance of German Afrika Korps had been halted only by making the famous 25-pounder field (see a separate article on this gun here) gun play the role of an anti-tank weapon. In May 1942, when the gun was approved for service, the 17-pounder was given a plain steel armour-piercing (A.P.) shot and a high-explosive (H.E.) shell. With a range of 9,144m (10,000 yards), the H.E. shell could change the powerful tank killer into a convenient field support gun, although this practice was used only very rarely as the standard 25-pounder field gun was usually available to fill this position. Anti-tank gun development soon showed that by far not everything can be achieved by means of gun design, at one point of increasing the muzzle velocity and the weight of shots and shells it was discovered that the intensity of impact shattered the projectile completely even before it could make any impression on the armour. But the ammunition development was ready to assist and soon the combination of both proved lethal to armour on both sides. Soon an armour-piercing shot with a steel penetrating cap (Armour-Piercing Cap or A.P.C.) was designed to transfer more of the blow to the shoulders of the projectile rather than the tip. The main drawback of the penetrating cap was its shape, ballistically disadvantageous. This was corrected and an armour-piercing ballistical cap (A.P.C.B.C.) projectile was adopted. But the development did not stop here as all these stages only put the real problems off and in the end they had to be dealt with. The Germans chose the way of producing guns which had a smaller calibre at the muzzle than at the chamber, which squeezed the tungsten shot to fit. The British took a different route and produced a tungsten core inside a full-calibre sabot or shoe, which split and dropped off upon leaving the barrel. |
 |
| The 17-pounder Field Gun Jan Hyrman The Battle of France and the subsequent north African campaign proved that tank design had kept up a rapid pace of development, while British service anti-tank guns remained the same and improvements had had a hard time getting into production. The 2-pounder anti-tank gun, accepted for service in October 1934, was often mocked for its small calibre (40mm) and inefficiency against enemy armour, however, the fact was that when the war broke out, it was the best weapon of its calibre in the world and could take out any German tank in service. Its possibility of smooth and rapid 360 degrees traverse on a three legged platform, and superb sights were supreme assets, it could be produced quickly and provided further logistical advantage of being also a standard tank gun (Covenanter, Matilda II, Valentine variants up to and including Mark VIIA, Crusader Marks I and II). However, all this was certainly much less correct when the war rolled into 1941. |
| Also, the Royal Navy was issued a modified manual loaded version of the gun to be mounted in turrets on gun landing craft to provide fire support for invasion troops. The British anti-tank artillery proved superior to its competition in the end, the muzzle velocities of the 2-pounder, 6-pounder and 17-pounder were all superior to its German and Soviet counterparts, however, all of these were considerably heavier. The ultimate stage of WWII British anti-tank artillery development (if we omit the huge 94mm 32-pounder, which never entered service), the 17-pounder with its superior range and muzzle velocity was certainly one of the best weapons available to the Allies. A dozen of these guns were also issued to the anti-tank battery of the Czechoslovak Independent Armoured Brigade Group and remained in service in the post-war Czechoslovak army until early 1950's. Sources: G.Forty: The British Army Handbook 1939-1945, Sutton Publications Inc., 2003 Ian V. Hogg: Allied Artillery of World War Two, Crowood Press, 1998 Ian V. Hogg: Allied Armour of World War Two, Crowood Press |
 |
| A Sherman Firefly looking for trouble. |
| A 17-pounder fired during WWII. The Czech writing above says: A 76mm anti-tank gun in action. Sometimes it is mounted in a Sherman tank. |
 |