25 mm caliber - Definition and Overview

Crewman relinking 25 mm rounds

The 25 mm caliber is a standard size of heavy machine gun (specifically autocannon) ammunition for NATO forces. The round itself has a length of approximately 8.5 inches (216 mm) while the projectile is approximately 4.5 inches (114 mm).

Usage

The 25 mm round can be used in both an anti-material and anti-personnel fashion. When operating in an infantry mode, a 25 mm weapon armed with HE rounds can effective kill large numbers of opposing troops either in the open or in light fortifications. When operating in an anti-material mode, a 25 mm weapon armed with AP 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, and as a standard ship-based munition in the Mk 38 autocannon.

Types of 25 mm ammunition

Several sub-types of 25 mm ammunition are available — the most common being Armor Piercing, High explosive, sabot, tracer, and practice rounds. Cartridges are usually comprised of a combination of the aforementioned categories. For example, the M791 pictured to the right is a Armor-Piercing Discarding Sabot with Tracer round. It is used against lightly armored vehicles, self-propelled artillery, and aerial targets such as helicopters and slow-moving, fixed-wing aircraft.

A diagram of the M791 25 mm round

25 mm caliber weapons

• the American M242 Bushmaster
• the American GAU-12 Equalizer
• the French GIAT M811
• the Swiss Oerlikon KBA

See also

• 30 mm caliber
• Caliber
• 5.56 mm caliber
• 7.62 mm caliber
• .50 BMG
• List of cartridges (weaponry), pistol and rifle

External links

• Federation of American Scientists: 25mm Ammunition (http://www.fas.org/man/dod-101/sys/land/25.htm)
• U. S. Army Field Manual 3-22.1
• UXO Safety Information (https://www.denix.osd.mil/denix/Public/Library/Explosives/UXOSafety/Photogallery/Small/smallmun.html)