A rifle is a firearm with a barrel that has a helical groove or pattern of grooves ("rifling") cut into the barrel walls, and is designed to be fired from the shoulder. This pattern is known as "rifling", and produces raised areas called "lands," which make contact with the projectile (for small arms usage, called a bullet), imparting spin around an axis corresponding to the orientation of the weapon. When the projectile leaves the barrel, the conservation of angular momentum improves accuracy and range, in the same way that a properly thrown American football or rugby ball behaves. The word "rifle" originally referred to the grooving, and a rifle was called a "rifled gun." Rifles are used in warfare, competitive target shooting, hunting and sport shooting.
Typically, a bullet is propelled by the contained deflagration of an explosive compound (originally black powder, later cordite, and now nitrocellulose), although other means such as compressed air are used in air rifles, which are popular for vermin control, hunting small game, and casual shooting ("plinking").
Originally the name "rifle" was short for "rifled gun"; but in many armed forces units it is thought wrong to use the word "gun" to mean a rifle. Furthermore, in many works of fiction a rifle refers to any weapon that has a stock and is shouldered before firing, even if this weapon is not rifled or doesn't fire solid projectiles.