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.).
Originally Posted by VitaMan
Wow oh wow, where did you find this crap?
There is no difference between a machine gun and an automatic weapon. Now you can break both of them down into the same categories, but the answer is they are both the same.
Originally Posted by the_real_Barleycorn
VM you need to stop pretending to be a firearms expert.
first of all, machine guns, automatic rifles, sub-machine guns and machine pistols are automatic weapons. these weapons fire automatically when a trigger is pulled.
they are not quite the same when it comes to function.
Machine guns are generally heavy, and they're usually carried by one or more persons or mounted on a vehicle/ship/aircraft. they are other lighter types of machine guns that can be carried by one person.
automatic rifles are essentially light machine guns.
sub machine guns and machine pistols are another type of light machine guns. I'd put them under as "feather weight" class.
don't know where you got that definition of assault rifle. there's no such mil spec definition of one. what you got is the media definition of one.