Oerlikon KBA
The Oerlikon KBA is a 25 mm (25×137mm) automatic cannon which was developed as a close-range multi-purpose weapon for the mechanized battlefield. It was originally manufactured by Oerlikon, and is currently produced at Rheinmetall Italia S.p.A. facilities. It features a positively locked breech and is gas and recoil-operated, with a rotating bolt head and a dual-belt ammunition feeding system using 25x137mm NATO ammunition. The rate of fire in burst mode is up to 600 rounds per minute, but it can be electronically adjusted and reduced to a selectable range between 100 and 175 rounds per minute, or single-shot mode.
Owing to its high firepower, wide range of available ammunition and the Instant Ammunition Selection Device, which allows the gunner to rapidly switch between two ammunition types, the KBA is capable of dual-mission employment. It can effectively engage a broad spectrum of targets, including armoured vehicles, infantry, anti-tank positions, helicopters, and counter-UAS threats, as well as loitering munitions.
Description
The Oerlikon KBA 25 mm is a fully automatic cannon based on the proven gas-operation principle with a rotating bolt head similar to the Mauser M 98 or M16 and double belt feed for the ammunition.The KBA offers a wide range of firing modes: single shot, programmable rapid single shot with a rate of fire programmable from 100 to 175 rds/min and full automatic fire up to 600 rds/min. The cannon functions, such as cocking and firing, are electrically actuated by a remote control unit or manually operated, in auxiliary mode, by means of a hand crank and a trigger pedal.
The Oerlikon KBA 25mm cannon has been designed for integration in various types of mounts, small size and low weight offering various integration possibilities such as:
- Manual gun mountings for armoured vehicles and naval vessels.
- Remote Controlled Weapon Stations for armoured vehicles and naval vessels.
- Air defence systems.
- Helicopter mounts.
History
At the turn of 1964-65, the US Army started the ambitious MICV-65 program to replace the M113 armored personnel carrier with a new infantry fighting vehicle. As an offshoot of MICV-65, the Bushmaster project aimed to create a new medium-caliber cannon for the US Army.The Bushmaster project was intended to meet the armament requirements of future infantry fighting vehicles of the 1980s and 1990s:
- Ammunition performance: penetrate 25mm of steel armour, at a 60° angle of impact, at 1000m range, corresponding to the armour of a well-armoured infantry fighting vehicle.
- Instant ammunition selection: for engagement of different targets.
- Selectable firing mode: Accurate single-shot, bursts with a rate of fire of more than 550 rds/min for engagement of aircraft.
- Compact structure: with low weight for installation in gun turrets of APCs.
- Simple to operate and service: in the hands of infantry.
TRW's requirements for the 25mm project were that the gun had to be fully automatic and actively locked, be operated by gas, have a rotating bolt head and use a dual-belt selective feed system allowing a quick and easy switch between different ammunition types. In parallel Oerlikon-Bührle assumed responsibility for developing the new 25x137mm ammunition and the interior ballistics of the TRW-6425.
The first prototype was produced in 22 months and began test firing in November 1965 from an Ml 14 vehicle. In December the prototype was fired from an Austrian Armored Personnel Carrier. An early version was tested by a number of countries including Great Britain and France. At the beginning of 1967, technical tests and firing trials were carried out with two TRW-6425 prototype cannons followed by the first demonstrations for a NATO country.
In the meantime the Swiss Oerlikon-Bürle factory obtained the European license for the TRW-6425 from TRW in 1967, and started the "KBA series" 25mm cannon project based on it. In the designation KBA, "K" stands for Kanone, "B" indicates 25mm caliber and "A" is the design model in a given caliber. Several principles were combined in order to refine the project.
At least six models of the TRW-6425 automatic cannons were built. The early configuration was tested several times at Aberdeen Proving Ground, included was a Military Potential Test from March 1968 to March 1969. Before the U.S. tests were completed the US Army paused the new IFV project due to the Vietnam War situation. At the end of 1969 TRW ceased work on the TRW 6425 cannon. In 1970 the Jet and Ordnance Division of TRW Inc. was closed and Stoner, together with Robert Bihun, launched ARES Inc. As ARES Inc. quickly outgrew Stoner's garage, they moved the company into the same buildings previously used by TRW Inc. and hired many of their former employees.
Following the closure of the TRW Jet and Ordnance Division, the Philco-Ford company's Aeronutronic Division became interested in the TRW-6425 cannon project, bought the rights to the project and began work on the weapon.
When the Bushmaster projectfull name U.S. Army Vehicle Rapid Fire Weapons System was restarted, the PFB-25 was selected as one of the self-powered gun candidates. Since then, Philco-Ford has further developed the PFB-25.
During the trials, the original American PFB-25 prototypes displayed a number of basic functional deficiencies. This prompted Oerlikon to undertake further development work on the KBA. Oerlikon extensively reworked the original American TRW 6425 design. Perhaps the only remaining elements of the original design in the KBA were the 25x137 mm cartridge and the method of blocking the chamber by turning the bolt. Eugene Stoner's classic automatic gas valve drive from the TRW-6425 cannon was also comprehensively changed. The resulting modifications added functional reliability that allowed the trials to be completed successfully in 1970. When the first prototype KBA cannons became available, suitable gun turrets had also to be provided.
The complete systemcannon, hand-driven turret and ammunitionunderwent detailed firing trials between 1969 and 1971.
Oerlikon devoted huge development efforts to improve the functional reliability, durability and firing precision of the KBA autocannon. In 1971 sufficient progress had been made for the weapon system to fulfill the strict specifications laid down and for large-scale deliveries to the Netherlands to begin.
In 1977, due to an internal decision, the US Army selected the externally-powered Hughes M242 from Hughes Helicopters Ordnance Division as the Bushmaster. The M242 became the autocannon for the Army's new IFV.
Within the framework of their product support service Oerlikon regularly improves the gun and ammuntion, and adapts them to the latest requirements. An important step forward was made in 1982/83 when the range at which the 25 mm APDS-T round achieves its specified performance was increased by 150% from 1000m to 2500m.
Ammunition
A wide range of ammunition has been developed for this weapon specifically developed to engage and defeat both ground and air targets. The ammunition complies with all handling and operational safety requirements according to MIL-STD's, and was subjected to intensive trials by NATO member countries prior to its introduction and standardization as NATO 25mmx137 ammunition.The current 25x137mm ammunition family consists in different combat and training rounds types as follow:
- APFSDS-T: Armour-Piercing Fin Stabilized Discarding Sabot with tracer, for use against armoured ground targets;
- APDS-T: Armour-Piercing Discarding Sabot with tracer, for use against armoured ground targets;FAPDS-T: Frangible Armour-Piercing Discarding Sabot with tracer, for use against air, ground and urban targets;SAPHEI-T: Semi-Armour-Piercing High Explosive Incendiary with tracer, for use against well protected targets;PELE: Penetrator with Enhanced Lateral Effect, for use against armoured ground targets without explosive charge;PELE-PEN: Penetrator with Enhanced Lateral Effect with Penetrator, for use against armoured ground targets without explosive charge;
- HEIAP: High Explosive Incendiary and Armor-Piercing, for use against armoured ground targets;HEI-T: High Explosive Incendiary with tracer, for use against lightly protected targets;HE-T: High Explosive with tracer, for use against lightly protected targets;MP-T: Multipurpose with tracer, designed to defeat a broad range of targets from soft skinned to armored target and building constructions;TPDS-T: Target Practice Discarding Sabot with tracer, a short range trainer for the above sub-calibre types;TP-T: Target Practice with tracer, used for training.
Mounting and Weapon Stations
These are the characteristics of the best-known KBA autocannon weapons stations in use and presently in production:VALHALLA
VALHALLA's MANGART 25 is a remote controlled SHORAD / multi-functional turret, designed for integration with modern wheeled or tracked armoured fighting vehicles.The MANGART 25 turret is designed to mount a 25mm Rheinmetall KBA autocannon paired with a high performance electro–optic system and a co-axial machine gun provides fire support for the main cannon.ASELSAN
The Aselsan STOP System is a turret system with Oerlikon KBA developed to be used against close and asymmetric threats on warships, coast guard boats, landing ships and other ships in order to contribute to increasing the defense capabilities of modern armies. It is included in a group of the Stabilized Machine Gun Platform System in the family of Stabilized Weapon Systems.The Aselsan NEFER-L is a remote controlled weapon station can be mounted on 4x4, 6x6 and 8x8 wheeled or tracked vehicles and is developed primarily for use against armored land targets. At the side of the main cannon a co-axial machine gun like 7,62mm provides fire support to the Oerlikon KBA.
LEONARDO
OTO Melara has developed a two-man turret for armored vehicles called HITFIST.. The turret is designed to mount a 25mm Oerlikon KBA or a 30mm ATK Mk44 autocannon. The main armament may mount a co-axial machine gun, a variant allows the operator to aim and fire anti-tank missiles. Current operators includes Italy, Poland and Romania.OTO Melara has also developed the OTO SINGLE 25mm KBA as a stabilized, electric servo-drive assisted weapon station, for naval applications, with 252 ready-to-fire rounds. It is made to neutralize targets in Anti-Surface Warfare, particularly in Asymmetric Warfare or Mine Defence scenarios, and thanks to the high rate of fire of the 25mm KBA cannon it also offers a capability in very close Anti-Air Defense. The OTO SINGLE 25mm KBA turret is available in both unmanned and manned configurations.
Others
The KBA 25mm Automatic Cannon is also installed in many other weapon station designs produced by different defense companies, here below a list of the most prominent:- FMC Turret Type EWS turret ;
- Israeli OWS-25R turret ;
- Lamborghini LM002 with KBA 25;
- OTO Quadruple Gun turret ;
- OTO T25S / T25 turrets ;
- OTO Spallaccia 25mm;
- Oerlikon GBD-ADA turret;
- Type 87 RCV turret.
Operators
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Potential operators
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