This is the Oerlikon KAA cannon used in a manually-controlled mounting built by BMARC (British Manufacture and Research Company) under the designation A41/820. Installed on many British warships after the Falklands War stimulated renewed interest in light machine guns.
"This cannon is essentially equivalent to the World War II Oerlikon 20 mm gun, with a higher muzzle velocity" - Norman Friedman in "The Naval Institute Guide to World Naval Weapon Systems 1991/92."
| Designation | Cannon: Oerlikon 20 mm/85 KAA
Mounting: GAM-BO1 |
|---|---|
| Ship Class Used On | Modern British warships
Exported to many countries |
| Date Of Design | N/A |
| Date In Service | about 1985 |
| Gun Weight | 203 lbs. (92 kg) without ammunition
401 lbs. (182 kg) with 200 round belt |
| Gun Length oa | N/A |
| Bore Length | 55.1 in (1.400 m) |
| Rifling Length | N/A |
| Grooves | N/A |
| Lands | N/A |
| Twist | N/A |
| Chamber Volume | N/A |
| Rate Of Fire | Cyclic: 900 - 1000 rounds per minute |
| Type | Fixed |
|---|---|
| Weight of Complete Round | N/A |
| Projectile Types and Weights | HE-I - 0.264 lbs. (0.120 kg) |
| Bursting Charge | N/A |
| Projectile Length | N/A
Length of Complete Round: 8.0 in (20.3 cm) |
| Propellant Charge | N/A |
| Cartridge | 20 x 128 mm (cartidge size is actually 128.7 mm) |
| Muzzle Velocity | 3,440 fps (1,050 mps) |
| Working Pressure | N/A |
| Approximate Barrel Life | N/A |
| Ammunition stowage per gun
(on mount) |
200 rounds |
| Elevation | Range |
|---|---|
| Effective - Surface | 2,200 yards (2,000 m) |
| Maximum | 7,450 yards (6,800 m) |
| Effective - Aircraft | 1,650 yards (1,500 m) |
"The Naval Institute Guide to World Naval Weapon Systems 1991/92" by Norman Friedman
"Jane's Ammunition Handbook: Ninth Edition 2000-2001" edited by Terry J. Gander and Charles Q. Cutshaw
"Rapid Fire" by Anthony G. Williams
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