When dealing with conventional automatic or semiautomatic man portable firearms, a failure to fire usually results in one having to manually clear the misfired round and chamber a new one.  What if there were a firearm that would automatically eject the misfired round and chamber a new round with another pull of the trigger (or in full auto by just keeping the trigger depressed), with enhanced reliability and higher mean rounds between failure than conventional firearms?  What if this same firearm also vented almost all gases forward for suppressed use in a semiautomatic or automatic format?  What if this same firearm also offered a programmable/variable rate of fire, a shorter receiver length than conventional arms, and is capable of forward ejection for ambidextrous use?  The technology exists.  Chain guns (the term “Chain Gun” is a registered trademark of Orbital ATK)  offer this capability.

M242 Bushmaster

What is a “Chain Gun”?

Chain guns, often confused with rotary-barreled guns such as the “minigun”, are single barreled guns operated by a linked chain.  This chain is attached to a “master link” that runs in a rectangular pattern on the receiver.  The chain drives a rotary bolt back and forth to complete the firing cycle, rather than relying on gas or recoil energy to cycle the firearm.  This allows the bolt to stay forward until up to 96% of propellant gases vent down the barrel before the next firing cycle.  The chain itself is powered by an electric motor that relies on an external power source.

Detail of a chain gun’s action. Image source: worldguns.ru

Notable chain guns in service are, among others:

• 30mm Mk44 (Used in the MC-130 Dragon Spear)
• 25mm M242 Bushmaster (M2 Bradley IFV)
• 30mm M230 (AH-64)
• Hughes EX-34/ H&K L94A1/ 7.62mm Bushmaster Chain Gun (Warrior IFV)

The latter iteration leads me to believe that further miniaturization and portability is possible.  The 7.62mm Bushmaster weighs only 30.2lbs/13.7kg, or only 4.4 more pounds than an M240B, and boasts a MRBF of 50,000 rounds.  In one test, two 10,000 round bursts were fired with no malfunctions.   Reliability is not an issue with chain guns.

M230, the Apache’s main gun

Possible portability

If these guns were modified to feed from a magazine, there could be a reduction in complexity, weight, width, height and power needed.  A shorter, thinner barrel for semiautomatic use would reduce weight as well.  Power supply would not be the biggest issue, as technology continues to get smaller and lighter in that arena.  The current model requires 26.5 volts of direct current, which can certainly be provided by a battery.  If a tracking point type sight mounted to the gun were slaved to a helmet-mounted display, such a weapon system would truly be the stuff of science fiction.  It’s easy to see, however, how developments in the defense industry are imitating art in that respect.  Configurations of chain gun rifles and/or pistols in many calibers could be possible.  What do you think, readers?  Will we live to see and utilize man-portable chain guns in our time?  Would such an operating system be useful for military, defensive, or sporting purposes?  This author believes so.

ATK’s improved 7.62mm Bushmaster Chain Gun with barrel shroud.  Ththough it has multiple fins around the muzzle, this is a single barrel gun, as to avoid any confusion with a “minigun” or gatling gun