A Sub-machine gun or machine pistol is a weapon that is designed to be fired from either the shoulder and/or the hip;is capable of full automatic fire;has a rifled barrel,and fires pistol ammunition.It is often incorrectly called a machine gun.Semi-automatic carbines (excluding the M-1 carbine) are a variation of sub-machine guns.These are either semi-automatic versions of sub-machine guns or weapons that have the external appearance of a sub-machine gun.The media has dubbed these "assault pistols"In the case of semi-automatic versions of sub-machine guns,the internal mechanism is typically so altered that they are essentially a different weapon.
A sub-machine gun is an automatic carbine designed to fire pistol cartridges.It combines the automatic fire of a machine gun with the cartridge of a pistol.The sub-machine gun was invented during the world war I but the zenith of its use was world war II when millions of this types were manufactured.Today,the sub-machine gun has mostly been replaced by the assault rifle for military use.The assault rifle uses an intermediate-power cartridge with more power than a pistol but less than a standard rifle or battle rifle.