Ordnance QF 20 pounder

Ordnance QF 20 pounder Mark I
Charioteer tank equipped with the 20 pounder. This gun is a later model which is fitted with a bore evacuator
Type	tank gun
Place of origin	United Kingdom
Service history
In service	1948-1970s
Used by	United Kingdom Australia Austria Canada Finland Israel Jordan Lebanon South Africa
Wars	Korean War Vietnam War Six Day War South African Border War
Specifications
Length	226.4 in (5.75 m)
Shell	20 pounds (9.07 kg)
Calibre	84 millimetres (3.31 in)
Elevation	+18 to -10 in Centurion Mk 5

The Ordnance QF 20 pounder (known as 20 pounder, 20 pdr or simply 20-pr) was a British 84 mm (3.307 inch)tank gun

It was introduced in 1948 and used in the Centurion main battle tank, Charioteer medium tank, and Caernarvon Mark II heavy tank.

It was the improved successor to the effective Ordnance QF 17 pounder and the predecessor of the 105 mm L7 gun.

The gun was developed by the Royal Ordnance Factories.

As fitted to the Charioteer, it ran through two models:

The L7 105 mm tank gun was developed from the 20 pounder. In 1954, the original version of the 105 mm was made by re-boring the tube of a 20 pounder barrel.

The gun was fitted predominantly to the Centurion tank, seeing action with British and Australian forces.

One gun was fitted to a Swiss pre-production Panzer 58.

The 20 pounder's APCBC projectile had an initial muzzle velocity of 1,020 metres per second and could penetrate 210mm of rolled homogeneous armour (RHA). However, these conventional rounds were rarely used.

The APDS projectile had a muzzle velocity of 1,465 m/s (4,810 ft/s) and could penetrate 30 cm (12 in) of RHA.

The 20-pounder could also fire high-explosive and canister shot shells.