The 17 Pounder Anti-Tank Gun

Like the 2 Pounder the 17 Pounder was originally planned to be a tank gun, in April 1941 the question of a weapon to replace the 6 Pounder was debated at a meeting by the Design Department and the artillery and tank branches of both the War Office and the Ministry of Supply. A this meeting it was decided that the new gun design must aim to be one piece common to both tank and anti-tank mountings and penetration of between 120-150mm - this would require a 3" gun firing a 17lb shell at around 2700fps. It was agreed that the carriage to mount the gun was to be of split-trial type and have a transverse of 60 degrees.

The prototypes were created and trials were completed at the beginning of 1942 and orders were placed. The first production guns were completed in April 1942 and by the end of the year 670 of the guns had been completed. There seems to be a lot of confusion as to the 17 Pounder carriage, the first production 17pdr carriages were completed in May 1942 but production was extremely slow, when the War Office issued urgent demands for 17 Pounder guns to be sent to North Africa there was not enough carriages available to mount the guns required so guns were mounted on 25 Pounder carriages instead, these were known as 25/17pdr carriages, codename Pheasant. 150 of these carriages were ordered and this order was completed by December 1942. In October 1942, 59 17 Pounder and 27,000 rounds of ammunition were shipped to the Middle East, I have not yet found the exact date of the guns arrival but they were definitely present by the end of December. In November/December a further 40 guns were sent. 

Concerns were raised at the weight of the equipment which would be around 3 tons, it was realised that this would clearly limit the mobility of the weapon and create delays when getting the weapon into and out of action and make concealment difficult. Due to these issues it was decided to mount the guns in a self propelled chassis, it was clear that no existing tank could accommodate the gun, the new cruiser tanks (Cavalier and Cromwell) had turrets designed around the 6pdr and their turret ring was too small (57.2") to mount the gun without crippling fighting efficiency. In the winter of 1941-1942 steps were taken to investigate a tank which could carry the new gun, by March 1942 this had crystallised into the A.30, this reached the prototype stage by August 1942 when production possibilities were being examined. This tank would later be accepted into service as the Challenger in 1944.

Many suggestions had been made for S.P. AT guns, originally it had been hoped that this requirement would be met by the US M10 but by July 1942 it was clear that there was no hope of getting these vehicles in quantity before 1943 so it became imperative to get a S.P. mounting for the 17pdr which was a better gun than the US 3" anyway. Both the Valentine and Crusader were investigated, the Crusader due to its high power to weight ratio and it's mobility  and the Valentine due to it's reliability and low profile. It was decided against the Crusader as it would have required the gun to be mounted in an exposed position with the minimum amount of protection. Other chassis investigated included the Canadian Ram. The Valentine was accepted with a longer term project which involved the Cromwell.

Further work was done on the problems of installing 17pdrs in a tank mounting, the guns were modified considerably to facilitate this work, principally this involved the adoption of a less bulky breech mechanism. In August 1943 the mounting of the 17pdr in a Sherman turret was pressed forward urgently as well as the mounting of 17pdrs in the M10. Firing trials of 17pdr mounted in the Sherman were completed in December 1943 and the first 20 vehicles were converted in January followed by the M10 in March. By the end of May 1944 527 vehicles mounted the 17pdr gun, by end of June this had risen to 831 and by the end of the May 1945 over 4000 vehicles mounted a 17pdr gun, also 743 Comets with a less powerful 17pdr variant had been completed.

The gun mounted on the Comet tank had a smaller breech block to enable it to be fitted inside the turret and cartridges from the 3" AA gun were used. The weapon fired the same projectiles as the regular 17pdr but as the cartridge was different the ammunition was not interchangeable, although the same calibre as the 17pdr the gun was named the 77mm HV in order to prevent confusion over ammunition supplies. The smaller cartridge meant a lower muzzle velocity and thus a decrease in performance compared with a regular 17pdr.

17 Pounder Ammunition

Both AP and APC ammunition were asked for at the same time in August 1941 with designs being completed by December. The first 10,000 AP rounds were delivered in June 1942 and first filling for service took place in September, first APC ammunition was filled in October 1942. APCBC ammunition was requested in the Summer of 1943 and first deliveries took place in the Spring of 1944. The original HE ammunition was found to be somewhat lacking so a reduced charge version was provided in the Summer of 1944, followed later in the year by a high capacity version. APDS based on the 6pdr APDS design was made available in June 1944 with the first ammunition being filled for service in July.

17 Pounder Gun variants

• Mk I - original version
• Mk II - intended for tank use (Challenger)
• Mk III - for navy unused
• Mk IV - for Sherman 
• Mk V -  for M10 
• Mk VI -  shorter breech block, for tanks
• Mk VII - for Sherman

17 Pounder Carriage and Gun data

77mm HV Gun data

17 pdr/77mm Projectiles

Penetration of the 17 pdr and 77mm guns (MQ plate, 30 degrees)

17 Pounder Carriage and Gun production by year (UK only)

17 Pounder Ammunition and 77mm production by year (Filled only, UK only)

77mm Ammunition production by year (Filled only, UK only)

Sources - Comet Handbook, 17pdr Handbook, AVIA 46 187, AVIA 22 511-514