Machine Gun

That's not a gun. This is a gun

Whatever happens, we have got. The Maxim gun, and they have not.
Hillaire Belloc The Modern Traveller (1898)

Basic Information

A fully automatic support weapon firing rifle calibre rounds, generally capable of sustained fire. Driven guns - that is, those which are capable of continuous sustained fire without actually being fully automatic due to their action being worked by an external force (such as a motor or an operator turning a crank) are often included due to their similarity.

In most modern militaries, this is what is meant by 'a gun' in the context of small arms.

Machine guns range from support rifles which some authorities would not allow into the class to things that stretch the definition of infantry weapons such as Heavy Machine Guns and Gatling Guns¹. In between the two extremes are found light machine guns, medium machine guns and general purpose machine guns. Medium and heavy machineguns, as well as general purpose guns in a sustained fire configuration, all come into the category of heavy weapons.

Ammunition is generally fed in by a belt of some kind or from a high capacity magazine or hopper … use of a small arms magazine is generally regarded as the hallmark of a support rifle.

A machine gun may be operated by one or more men - most of the larger varieties need to be at least partially disassembled to be moved and in any case the quantity of ammunition that they consume will require someone, or something, to assist with transporting it since the gun alone is generally a fairly heavy load. Machinegun crew often carry pistols, submachine guns or carbines as back-up weapons.

The machine gun appeared on the battlefields of the world in the second half of the 19th Century - although previous attempts at building rapid firing anti-personnel weapons had been made before then. Where they were well employed they were predictably devastating against massed infantry - especially against primitive opponents in colonial conflicts - but mistakes in the early doctrines developed for their use lead to them being treated as artillery (e.g. during the 1870 Franco-Prussian War by the French, or by the British in the Second Boer War) which lead to them being thought less effective against a 'modern' army. Thus the start of WW1 found many armed forces poorly equipped with machine guns, despite the dominant role they were to have in the coming conflict.

Arguably the development of the machine gun spelled the end of massed infantry tactics and the tactical use of cavalry and led to the invention of the tank and modern "empty battlefield" tactics.

Specific Examples

The Bira Gun - technically not a machinegun, but something similar enough to include in the broad category.

Sources

Bibliography

1. full source reference

Game and Story Use

• In a late 19th century game, the machine gun allows the PCs to make their heroic stand against the massed army of bloodthirsty natives, or is the secret superweapon that they must recapture from the enemy spies.
• In a modern campaign a machine gun should be a complete change of pace and a signal that the PCs are now up against some serious opposition.
  • Unless it's a military campaign, in which case they are more part of the furniture.
  • Finding a way to silence a well emplaced gun in the absence of heavy support was a common challenge for infantrymen in the more open fronts of WW1 and WW2 and a good mini mission for military PCs.
• So the PCs have a gun? Then they have a whole new set of challenges to keep it in ammunition, fresh barrels and other sundry spares. And they're very, very heavy. In most non-warfare circumstances, a gun is far too much gun for the job in hand.

Footnotes

1. Although very few - if any - Gatling type weapons are actually machine guns, the majority of them being driven in one way or another.