M242 Bushmaster

The M242 Bushmaster is a 25 mm (25×137mm) chain-driven autocannon. It is used extensively by the US armed forces, as well as by NATO's and some other nations' forces in ground combat vehicles and watercraft. Originally, the weapon was designed and manufactured by McDonnell Douglas (later acquired by the Boeing Corporation); however it is now produced by Alliant Techsystems (ATK) of Mesa, Arizona.

It is an externally powered, chain driven, single-barrel weapon which may be fired in semi-automatic, burst, or automatic modes. It is fed by a metallic link belt and has dual-feed capability. The term "chain gun" derives from the use of a roller chain that drives the bolt back and forth. The gun can destroy lightly armored vehicles and aerial targets (such as helicopters and slow-flying aircraft). It can also suppress enemy positions such as exposed troops, dug-in positions, and occupied built-up areas. The standard rate of fire is 200 rounds per minute. The weapon has an effective range of 3,000 metres (9,800 ft), depending on the type of ammunition used. With over 10,000 units sold worldwide it is one of the most successful modern autocannons.

M242 Bushmaster
Class Manportable
Type Machine Guns
Manufacturer Alliant Techsystems
Origin United States of America
Country Name Origin Year
United States of America 1972
Country Name Operational Year Retirement Year
Australia View
Canada View
Ceylon (Sri Lanka) View
Israel View
Malaysia View
Philippines View
Singapore View
Spain View
Switzerland View
Turkey (Ottoman Empire) View
United Kingdom - UK (Great Britain) View
United States of America 1972 View
Norway View
New Zealand View
ManufacturerName Production From Production To Quantity
Alliant Techsystems 10500 View

The Bushmaster project started as an offshoot of the US Army's MICV-65 program that was attempting to introduce a new infantry fighting vehicle to replace their existing M113s. Part of this program called for a new scout vehicle to replace the M114, a parallel development taking place under the XM800 Armored Reconnaissance Scout Vehicle. Both the XM800 and the cavalry version of the XM701 MICV vehicles were armed with the M139, a US-built version of the Hispano-Suiza HS.820 20 mm autocannon.

During the testing phase, the Army eventually rejected the XM701 and started work on a newer design known as the XM723. Soon after the XM800 was also rejected. This led to the combination of the two programs, moving the scout role to the cavalry version of the XM723.

At the same time, the M139 proved to be disappointing and a contract for a new weapon to replace it started in 1972 at Hughes Aircraft as the Vehicle Rapid-Fire Weapons System-Successor, or VRFWS-S. This was essentially a power-driven gun firing similar ammunition as the HS.820, the power-driven mechanism would ensure operation even in the case of a misfire.

Progress on the VRFWS-S was slow, and eventually resulted in a switch to a much more powerful 25 mm round. Similar delays in the MICV program meant the ultimate vehicles descending from their efforts, the M2/M3 Bradley Fighting Vehicle, did not enter production until 1981, by which point the Bushmaster had matured. Since 1990, there have been several enhancements made upon the weapon, resulting in the Enhanced 25 mm gun.

To date, more than 10,500 weapons are in service. One of the major reasons for this popularity is the extremely reliable nature of the weapon. It has a rating of 22,000 mean rounds between failure (MRBF), much higher than many comparable devices.

Type Chain gun
Place of origin United States
Service history
In service 1972–present
Used by See operators
Production history
Designer McDonnell Douglas
Manufacturer Alliant Techsystems
Number built 10,500+
Specifications
Weight 119 kilograms (262 lb)
Length 2,527 mm (99.5 in)
Barrel length • Overall: 2,672 mm (105.2 in)
• Bore: 2,175 mm (85.6 in)
Width 318 mm (12.5 in)
Height 373 mm (14.7 in)
Shell 25×137 mm
Caliber 25 millimetres (0.98 in) caliber
Barrels Single barrel (progressive RH parabolic twist)
Rate of fire • Cyclic: 200rpm with 1hp or 500rpm with 8hp
Muzzle velocity 1,100 metres per second(3,600 ft/s)
Effective firing range 3,000 metres (9,800 ft)
Maximum firing range 6,800 metres (22,300 ft)

End notes