A rifle is a portable, long-barrelled firearm designed for accurate long-range shooting, to be held with both hands and braced against the shoulder for stability during firing, and with a barrel that has a helical pattern of grooves ("rifling") cut into the bore wall. The term was originally rifled gun, with the word "rifle" referring to the machining process of creating groovings with cutting tools, and is now used for any long handheld device designed for well-aimed discharge activated by a trigger, such as the personnel halting and stimulation response rifle. Rifles are used extensively in warfare, law enforcement, hunting and shooting sports.
Like all typical firearms, a rifle's projectile (bullet) is propelled by the contained deflagration of a combustible propellant 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, formal target shooting and casual shooting ("plinking"). The raised areas of a barrel's rifling are called "lands", which make contact with and exert torque on the projectile, imparting a spin around the longitudinal axis of the barrel. When the projectile leaves the barrel, this spin lends gyroscopic stability to the projectile and prevents tumbling in flight, in the same way that a spirally thrown American football or rugby ball behaves. This allows the use of aerodynamically-efficient bullets (as opposed to the spherical balls used in muskets) and thus improves range and accuracy.