What is the difference between a machine gun and an automatic weapon?
Originally Posted by the_real_Barleycorn
Automatic firearms can be divided into six main categories:
Automatic rifle
The standard type of service rifles in most modern militaries, usually capable of selective fire. Assault rifles are a specific type of select-fire rifle chambered in an intermediate cartridge and fed via a high-capacity detachable magazine. Battle rifles are similar, but chambered in a full-powered cartridge.
Automatic shotgun
A type of combat shotgun capable of firing shotgun shells automatically, usually also semi-automatically.
Machine gun
A large group of heavier firearms used for suppressive automatic fire of rifle cartridges, usually attached to a mount or supported by a bipod. Depending on size, weight and role, machine guns are divided into heavy, medium or light machine guns. The ammunition is often belt-fed.
Submachine gun
An automatic, short rifle (carbine) typically chambered for pistol cartridges. Today seldom used in military contexts due to a rise in the use of body armor, they are commonly used by police forces and close protection units in many parts of the world.
Personal defense weapon
A new breed of automatic firearms that combines the light weight and size of the submachine gun with the medium power caliber ammunition of the rifle, thus in practice creating a submachine gun with body armor penetration capability.
Machine pistol
A handgun-style firearm, capable of fully automatic or burst fire. They are sometimes equipped with a foldable shoulder stock, to promote accuracy during automatic fire, creating similarities to their submachine gun counterparts. Some machine pistols are shaped similarly to semi-automatics (e.g., the Glock 18, Beretta 93R). As with SMGs, machine pistols fire pistol caliber cartridges (such as the 9mm, .40, .45 ACP etc.).
