25 mm caliber is a range of autocannon ammunition. It includes the NATO standardized Swiss 25×137mm, the Swiss 25×184mm, the Soviet 25x218mmSR, and the Chinese 25×183mmB.

Usage

The 25 mm round can be used in both an anti-materiel and anti-personnel fashion. When operating in the anti-personnel role, a 25 mm weapon armed with HE rounds can effectively kill large numbers of opposing troops either in the open or in light fortifications. When operating in the anti-materiel role, a 25 mm weapon armed with armor-piercing rounds can disable many aircraft and vehicles, including some main battle tanks.

The US military uses 25 mm weapons in their AV-8B Harrier, AC-130 gunship, M2 Bradley, LAV-25, F-35 Lightning II and as a standard ship-based munition in the Mk 38 autocannon.

Types of 25 mm ammunition

Several sub-types of the NATO 25 mm ammunition are available—the most common being armor-piercing, high-explosive, sabot, tracer, and practice rounds. Cartridges are usually composed of a combination of the aforementioned categories. For example, the M791 is an armor-piercing discarding sabot with tracer (APDS-T) round. It is used against lightly armored vehicles, self-propelled artillery, and aerial targets such as helicopters and slow-moving fixed-wing aircraft.

25 mm weapons

Each weapon is listed with its cartridge type appended.

Current weapons

• Oerlikon KBA: 25×137mm
• M242 Bushmaster: 25×137mm
• GAU-12/22 Equalizer: 25×137mm
• GIAT M811: 25×137mm
• Oerlikon KBB: 25×184mm
• Oerlikon KBD: 25×184mm
• Type 61: 25×218mmSR
• Type 95 SPAAA: 25×183mmB
• ZPT-90: 25×183mmB

Historical weapons

• 25 mm Hotchkiss anti-aircraft gun/Type 96 25 mm AT/AA gun: 25×163mm
• 25 mm Hotchkiss anti-tank gun: 25×193.5mmR
• 25 mm M1940 anti-aircraft gun: 25×218mmSR
• 25 mm Bofors M/32 anti-aircraft gun: 25x205mmR (initial) or 25x187mmR (later)