Canada in the Second World War

Arms & Weapons

Anti-Tank Guns and Projectiles

Anti-Tank Guns

Soldier firing 6-pounder anti-tank gun at the end of a street in Ortona, Italy, 21 December 1943.

Soldier firing 6-pounder anti-tank gun at the end of a street in Ortona, Italy, 21 December 1943.
Photo by Terry F. Rowe. Department of National Defence / National Archives of Canada, PA-141671.

The evolution of tank design throughout the war goes hand-in-hand with that of anti-tank weapons. As larger and more powerful armoured fighting vehicles appeared with progressively heavier armour protection, new guns and new types of ammunition were developed to defend against them. Until the spring of 1941, the main tank and anti-tank (AT) gun used by the British and Canadian armies was the 2-pounder (British guns were frequently named for the weight of projectile they fired).

 

 

 

 

 

 

2-Pounder Field Gun
Ordnance
Weight with breech mechanism 130 kg
Total weight in action 800 kg
Length 2.08 m
Rifling one turn in 30 calibres
Breech vertical sliding block
Elevation -13° to +15° on platform; -5° to +23° on wheels
Traverse 360° on platform; 14° left and 10° right on wheels
Performance
Projectile Mark 10T Mark 9BT
Type AP APCBC
Weight of projectile 0.91 kg 0.91 kg
Muzzle velocity 808 m/sec
Penetration at 1000 yards (30° impact) 42mm
Maximum range 8000 yards
Personnel of the Royal Canadian Artillery with a 17-pounder anti-tank gun in Normandy, 22 June 1944.

Personnel of the Royal Canadian Artillery with a 17-pounder anti-tank gun in Normandy, 22 June 1944.
Photo by Ken Bell. Department of National Defence / National Archives of Canada, PA- 169273.

It had been realised even before the war that a heavier gun was needed, and by 1939 the 6-pounder had been developed, though it did not enter production until November 1941. Following the Dunkirk evacuation, it was decided to continue 2-pdr production because converting the factories for the larger gun would take time. The British were desperately short of guns, and a German invasion was imminent. The 6-pdr subsequently became the main British and Canadian anti-tank gun. For much of the war it was also the standard tank armament, being mounted in Ram and Churchill tanks, among others. By the time of the Normandy invasion in June 1944 the 6-pdr had largely been replaced in tanks and in anti-tank regiments, although it continued to be widely used by the infantry in an anti-tank role.

6-Pounder Field Gun
Ordnance(Gun Mark II on Carriage Mark I)
Weight with breech mechanism 350 kg
Total weight in action 1145 kg
Length 30.77 m
Rifling one turn in 30 calibres
Breech vertical sliding block
Elevation -5° to +15°
Traverse 45° right and left
Performance
Projectile Mark 1 to Mark 7T Mark 8T Mark 9T Mark 1T
Type AP APC APCBC APDS
Weight of shot 2.72 kg 2.84 kg 3.18 kg 1.47 kg
Muzzle velocity 820 m/sec 845 m/sec 1235 m/sec
Penetration at 1000 yards (30° impact) 74 mm 88 mm 146 mm

The search for a larger gun to replace the 6-pdr led the British to develop the 17-pdr, and issue to the Royal Artillery began in late 1942. The first 17-pdrs had been rushed off to North Africa on 25-pdr carriages to counter the new German Tiger tanks, while development of a proper carriage suited to the 17-pdr continued. By mid-1944 the 17-pdr had become the main weapon in most anti-tank regiments, and a modified version had been fitted into a limited number of Sherman “Firefly” tanks. With the Firefly the British and Canadians had a weapon to compare with the powerful German anti-tank guns. Unfortunately, it was available only in relatively small numbers, and the Americans opted not to use it, preferring to develop their own 76.2 mm gun. Most 17-pdrs were towed, but a self-propelled (SP) variant called the “Archer” featured the gun mounted on a Valentine chassis. It was conspicuous in that the gun was fitted facing the rear of the vehicle. Another SP variant was the “Achilles”, basically an American M10 tank destroyer substituting the 17-pdr for the original 3-inch anti-aircraft gun.

17-Pounder Field Gun
Ordnance
Weight with breech mechanism 826 kg
Total weight in action 2100 kg
Length 4.2 m (55 calibres)
Calibre 76.4 mm
Rifling one turn in 30 calibres
Breech vertical sliding block
Elevation -6° to +16.5°
Traverse 30° right and left
Performance
Projectile Mark 1T Mark 3T Mark 4T Mark 1T
Type HE AP APC APDS
Weight of Projectile 7 kg 7.7 kg 7.7 kg 3.4 kg
Muzzle velocity 885 m/sec 885 m/sec 1200 m/sec
Penetration at 1000 yards (30° impact) 109 mm 118 mm 231 mm

Anti-Tank Projectiles

Anti-tank (AT) guns initially used solid steel armour piercing (AP) rounds which derived their penetrating power from kinetic energy. As armour increased in thickness it became necessary to achieve higher muzzle velocities in order for a projectile to penetrate, but steel shot tended to shatter on impact at velocities upward of about 823 metres (2700 feet) per second. A variety of projectile types were developed to maximize muzzle velocity and penetrating power. A soft metal cap was added first to try to prevent the solid shot from shattering. It was found that these APC, or armour piercing, capped, rounds were unstable in flight, however, and so a ballistic cap was introduced in APCBC (armour piercing, capped, ballistic capped) rounds to improve range and accuracy. The best solution to the problem was found in armour piercing, discarding sabot (APDS) rounds, introduced in August 1944. Development had been influenced by Canadian General A.G.L. McNaughton, a gunner of the Great War who had commanded the Canadian Army in Britain until November 1943. APDS rounds featured a tungsten-carbide core projectile within a steel jacket that was shed upon leaving the muzzle. Tungsten-carbide was expensive to produce, and so heavy that a full-bore projectile could only be fired at relatively low muzzle velocities. By using the discarding jacket, however, the full force of the exploding propellant was applied to a ballistically-superior and very dense core, resulting in much higher muzzle velocities and improved penetrating power.

Eventually, the upper threshold of development of kinetic energy anti-tank weapons was reached, after which guns became too large to be practicable. Instead of kinetic energy resulting from high velocity, shaped- or hollow-charge projectiles relied on explosive chemical energy. When such a projectile struck, “a fuse detonated explosive at the end remote from the shaped cavity at the front of the round and . . . created a jet of molten metal that would penetrate armour plate and spray a mass of flame and melted metal fragments into the interior of a tank. Hollow charge projectiles were ideal for low-velocity, hand-held anti-tank weapons” such as the British PIAT (Projector, Infantry, Anti-Tank), the American bazooka, and the German Panzerfaust and Panzerschreck (Donald E. Graves, South Albertas: A Canadian Regiment at War, 1998, p. 365).