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.svg.png){kind=small} 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 (simply known as 20 pounder or 20-pr) was a British 84 mm (3.307 inch)[1] 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.
Design and Development
The gun was developed by the Royal Ordnance Factories.
As fitted to the Charioteer, it ran through two models:
- Model A without a fume extractor.
- Model B with a fume extractor.
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.[2]
Service history
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.[3]
Performance
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.[4][5]
The 20-pounder could also fire high-explosive and canister shot shells.
Ammunition
| Round | Muzzle velocity[6] |
|---|---|
| APDS | 4,700 ft/s |
| HE | 1,975 ft/s |
| Canister | 3,000 ft/s |
| Smoke | 825 ft/s |
Notes
- ↑ Pugh, p.34; the gun is specified as 83.4 mm (3.283 in) here, while Ogorkiewiecz states the weapon was 83.8 mm. Norman gives it as "3.3 inch (84 mm)"
- ↑ Ogorkiewicz, p. 70.
- ↑
- Ford, Roger (1997). The World's Great Tanks from 1916 to the present day. Brown Packaging Books Ltd. p. 121. ISBN 1-897884-29-X.
- ↑ British Anti-Tank Gunnery Data at www.figuras.miniatures.de
- ↑ Dunstan, p. 10, notes the 20 pounder's APDS round had twice the penetration capability of an 8.8 cm AP round.
- ↑ Norman p12
References
- Dunstan, Simon. Centurion Universal Tank 1943-2003, Oxford: Osprey Publishing, 2003. ISBN 1-84176-387-X.
- Ogorkiewicz, Richard. Technology of Tanks, London: Jane's Information Group, Ltd., 1991. ISBN 0-7106-0595-1.
- Pugh, Stevenson (1962). Fighting Vehicles and Weapons of the Modern British Army. Macdonald & Co. OCLC 10010960.
- Norman, Michael. Armour in Profile No. 23 Centurion 5. Surrey: Profile Publications.
See also
- Pounds as a measure of cannon bore
- British standard ordnance weights and measurements
- Ordnance QF 32-pounder
External links
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Wikimedia Commons has media related to QF 20 pounder. |