What is the different between sub machine gun and rifle?

Answer 1

Submachinegun refers to a fully automatic firearm that fires a pistol caliber cartridge, such as 9mm parabellum or .45 ACP. Rifle refers to a firearm that is fired from the shoulder, and has a barrel designed to make a bullet spin as it leaves the barrel, increasing its accuracy. Most commonly this is by having spiral grooves (rifling) cut into the inside of the barrel. PS- machineguns and handguns ALSO usually have rifling in their barrels.

The lines between a submachinegun and a rifle/carbine have been blurred at times, though. The Heckler & Koch HK33, which fires the 5.56mm cartridge common to the M16, was marketed by the company as a submachinegun, for example, even though it fires a dedicated rifle cartridge.

Traditionally, submachineguns fired pistol caliber cartridges (as stated above) and fired from the open bolt. However, designs such as the MP5, which fired from the closed bolt, began to appear, and altered the definitive archetype of what a submachinegun was. And now the Personal Defence Weapon class of firearm is emerging, with new designs somewhere between a submachinegun and a rifle, and with cartridges which are somewhere between handgun and rifle cartridges.