Rather than being gas operated, an electric motor operates a chain link which in turn operates the firing mechanism. This way, if a round fails to fire, it is still extracted, ejected, and replaced with a fresh round.
Don't know about the gun you are asking about, but there IS a firearm known as a Chain Gun. The 25mm cannon used by the US military Bradley armored vehicle is a chain gun.
chain gun is something you need for one of the hitman jobs. level up and then this gun will be made available to u
a chain gun
Bushmaster
The advantage of a chain gun--a machinegun that uses an electric motor connected to the gun with a drive chain--is that the motor makes the gun's cycle of function more reliable when the gun gets dirty from firing or from being in a dirty environment. The motor can pull the spent cartridge casings out of the chamber more reliably than a recoil-operated or gas-operated gun can.
The M230 chain gun was developed by Hughes. It is now manufactured by Alliant Techsystems. Designed in 1975, this is actually an automatic cannon and is mounted on a helicopter.
Impossible to answer without knowing the caliber.
In Gears of War the lancer is the gun with the chain saw bayonet
The chain gun
gun shop
You are probably thinking of an externally powered machine gun, such as the 25mm autocannon on the M3 Bradley. However, manually powered chain guns, such as the Josselyn Revolver were patented in 1866.
shake the telephone :)