30mm Hispano-Suiza HS.831
Oerlikon KCB
Overview
30mm GCM-A03-2
A 30mm GCM-A03-2 seen on a Royal Navy Type 22 frigate.
Source: Royal Navy -
© Crown copyright
Early 1950's for HS.831A
Late 1950's for HS.831L
Late 1940's - Early 1950's for HS.831A
Late 1950's for HS.831L
Late 1950's - Present? (HS.831L / KCB)
Switzerland - Oerlikon-Contraves (since 1970)
Description
Introduction
The Hispano-Suiza HS.831 is an early Cold War era autocannon of Swiss origin. It is a post-war development of the HS.830 developed in 1944. It also shares many similarities with the 20mm HS.820 developed at the same time. Present day it is better known as the Oerlikon KCB. This is the improved HS.831L model in the Oerlikon line-up after Oelikon acquired the armament division of Hispano-Suiza in 1970.
Design
The HS.831 is a single barrel autocannon. It uses a gas unlocked blowback action. Upon firing the gas action unlocks the action, making the blowback action less violent but still powerful enough to cycle the action. This autocannon is uses a magazine feed or a single belt feed mechanism, feeding from either from the left or right. The HS.831L is an updated version developed in the late 1950's to achieve a higher muzzle velocity required in Swiss testing. It fires a new range of ammunition which has lighter projectiles with higher muzzle velocity, extending the practical range as an anti-aircraft gun.
Firepower
The original HS.831A has a cyclic rate of fire of 600 rpm. This was increased to 650 rpm in the later HS.831L. The ammunition for the HS.831L is ballistically matched for a muzzle velocity at 1.080 m/s. The manufacturer claims an effective range against aircraft of 2.5 km, against surface targets of 3.25 km and the ballistic slant range is about 6 km.
Platforms
Initial use of the HS.831A was on a tripod mount for anti-aircraft use, introduced around 1955. This was quickly supplemented by the HS.661B mount with much better fire control and smooth traverse, making maximum use of the 2.5 km practical range potential. The French AMX-13 DCA mounts two HS.831A autocannon, as does the larger chassis AMX-30 DCA sold to Saudi Arabia. The HS.831L was also used on a variety of manned naval mounts, sometimes with additional off mount fire control. These include the twin barrel GCM-A, single barrel DS30B and twin barrel Emerlec-30.
Variants
30mm Hispano-Suiza HS.831A
Forward view of two 30mm Hispano-Suiza HS.831A autocannon seen on a derelict AMX-13 DCA self-propelled anti-aircraft gun at the Saumur tank museum.
Source: Victor den Bak -
© Public domain
List of HS.831 variants
Details
Application
30mm HS.661 (early model)
An early predecessor of the HS.661B gun mount was fitted with the HS.831A autocannon and was fed by a drum magazine.
30mm HS.661B
The HS.661B single gun anti-aircraft gun is fitted with the HS.831L. Fed by a box magazine holding 8 stripper clips of 5 rounds each.
AMX-30 DCA
The AMX-30 DCA is a further development of the AMX-13 DCA using the larger AMX-30 tank chassis.
K30 Biho
South Korean self-propelled anti-aircraft gun. Armed with two Oerlikon KCB (HS.831L) autocannon.
30mm Oerlikon GCM-A03
Two Oerlikon KCB autocannon are used in the GCM-A series of naval gun mounts. These feature either local or remote control.
30mm Emerlec EE-30
Two Oerlikon KCB autocannon are used in the Emerlec 30 naval mount.
30mm DS30B Mark I
A single KCB autocannon is fitted in the DS30B (previously called LS30B) naval gun mount.
Related articles
20mm Hispano-Suiza HS.820
The HS.831 uses the same operating mechanism as the 20x139mm HS.820 autocannon. In 1970 this also became part of the Oerlikon product line-up as the KAD.