The M242 25mm Chain gun

A chain gun is a type of machine gun or autocannon that uses a external source of power, rather than recoil, to cycle the weapon.

The primary advantage of chain-driven weapons over their recoil-actuated counterparts is their reliability. Rather than being dependent upon recoil to actuate the system, a chain gun instead depends on an external motor. The motor drives the chain, which slides the bolt assembly back and forth to load, fire, extract and eject cartridges. Since the speed of the motor controls how fast the weapon fires, another advantage of the chain gun is its ability to accurately control the rate of fire.

In the case of a round not firing properly, the chain gun continues on, ejecting it along with the spent casings. In a recoil-actuated weapon, a misfire can cause serious problems, especially in the case of fully automatic weapons.

Examples

The most commonly produced and used chain gun is the M242 Bushmaster. Versions of its 25mm action are found on ships (the Mk38), Infantry fighting vehicles (the M2 Bradley), and LAV-25 around the world. Other examples of chain guns include the M230 30mm Cannon, which is standard equipment on the Apache helicopter, as well as the Bushmaster II 30mm , and the Bushmaster III 35/50mm Chain gun .

It is a common misnomer to refer to Gatling guns (rotary cannons) as chain guns. Certain Gatling guns do use a chain gun mechanism, however all Gatling guns are not inherently chain-powered weapons. Weapons such as the M61 Vulcan, the M197, the M134, and the XM214 are chain-powered Gatling guns.

External links

• U. S. Army TACOM-RI

Sources

• U. S. Army Field Manual 3-22.1