Weapon consisting essentially of a metal tube from which a missile or projectile is shot by the force of exploding gunpowder or some other propellant.
The term is often limited today to the so-called big guns, cannon larger than a howitzer or mortar . It may also be used to refer to military small arms such as the rifle , machine gun , and pistol , as well as to nonmilitary firearms such as the shotgun . Though the Chinese used gunpowder in warfare from the 9th century, guns were not developed until the Europeans acquired gunpowder in the 13th century. The earliest guns ( 0441; 1327) resembled old-fashioned soda bottles; they apparently were fired by applying a red-hot wire to a touchhole drilled through the top. Separating the barrel and the powder chamber resulted in breechloaders, which continued to be used in naval swivel guns and fortress wallpieces well into the 17th century. Small arms, as distinguished from hand cannon, did not exist until the development of the matchlock in the 15th century. See also flintlock , wheel lock .