Description
25mm Oerlikon Type KBB APDS-T Round, 25×180mm
This uncommon 25mm cartridge was developed for the Oerlikon Type KBB automatic cannon. It is an Armor-Piercing Discarding-Sabot with Tracer, or APDS-T, round. The longer 25×180mm case gave the KBB greater velocity, range, and armor penetration than the earlier 25×137mm Oerlikon cartridge. This listing is for one cartridge assembly only. It does not include a cannon, ammunition container, belt link, display stand, or accessories.
Identification and Markings
The black projectile is marked APDS-T and 03 OER 84. The green cartridge case has the visible head markings 038 and 86, along with a circular manufacturer mark. These markings appear consistent with an Oerlikon projectile produced in 1984 and a case dated 1986, but no exact lot-code interpretation is claimed. The cartridge has a green-finished bottleneck case and a black discarding-sabot projectile with a pointed nose.
How the APDS-T Round Works
A discarding sabot carries a smaller armor-piercing penetrator through the cannon barrel. After the projectile leaves the muzzle, the sabot separates and the narrow penetrator continues toward the target at high speed. A tracer element makes the projectile’s path easier to observe. The APDS-T projectile relies on speed and impact rather than a high-explosive bursting charge, although an unmodified cartridge may still contain a primer, propellant, and tracer composition.
Published Specifications
Caliber: 25mm
Cartridge designation: 25×180mm
Other designation: Oerlikon Type KBB
Ammunition type: APDS-T
Published complete cartridge weight: 550 grams, approximately 1.21 pounds
Published projectile weight: 150 grams, approximately 5.29 ounces
Published muzzle velocity: 1,460 meters per second, approximately 4,790 feet per second
Case type: Rimless, bottlenecked case
Intended weapon: Oerlikon KBB 25mm automatic cannon
Original developer: Oerlikon
Development period: Early 1980s
Cartridge Designation and Compatibility
A 1985 U.S. defense identification guide lists this cartridge as 25×180mm. Some later catalogs identify members of the KBB cartridge family as 25×181mm or 25×184mm because reported case measurements can vary by load and reference. This is not the standard 25×137mm cartridge used by the Oerlikon KBA, M242 Bushmaster, or GAU-12/A. The longer KBB cartridge is not interchangeable with 25×137mm ammunition.
Oerlikon KBB Cannon History
Oerlikon developed the KBB during the early 1980s as a high-performance 25mm gas-operated, belt-fed automatic cannon. Its longer cartridge offered improved speed, range, and penetration while retaining a compact ammunition size. The KBB ammunition family included APDS-T, high-explosive incendiary, anti-missile discarding-sabot, and practice cartridges. APDS-T filled the high-velocity armor-piercing and tracer role within that family.
Sea Zenith Weapon System and History of Use
The best-known operational application of the KBB was the Oerlikon-Contraves Sea Zenith close-in weapon system. Sea Zenith placed four KBB cannons in a radar-directed naval mount with a combined firing rate of about 3,200 rounds per minute. The unusual rear-leaning mount could elevate sharply to engage diving threats. The Turkish Navy installed Sea Zenith systems aboard Yavuz- and Barbaros-class MEKO 200 frigates for close-range defense against aircraft, missiles, and surface threats. Different KBB ammunition types were selected for different targets, with APDS-T intended mainly for high-speed fire against hard targets and for visible tracer observation.
Collector and Display Value
The specialized KBB cartridge was far less common than the widely used 25×137mm family. Its Cold War development, Oerlikon markings, dated components, and connection to the Turkish Navy’s four-gun Sea Zenith system make it an unusual item for military-ammunition, naval-weapons, autocannon, and defense-technology collections.
Condition and Safety Notice
The photographs do not establish whether this cartridge is live, expended, demilitarized, or fully inert. Do not assume it is safe based on appearance alone. A qualified person should verify that the primer, propellant, tracer composition, and other energetic materials have been removed or made permanently inert before handling, shipment, transfer, or display. Follow all applicable laws and carrier requirements.
Approx length 9", Approx width 1.5", Approx height 1.5", Approx weight 0.9 lbs.
Pictures are stock images of our inventory. Unless otherwise noted, you will not be receiving the exact item shown in the pictures. The pictures are representative of the item’s general condition. The item you receive might be slightly better, or worse, condition than was shown in the pictures.
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