An air rifle is a type of gun that uses compressed air or other gases as a propellant to fire projectiles down a rifled barrel. Air rifles come in both long gun and handgun forms, and they typically propel metallic projectiles that are either diabolo-shaped pellets or spherical shots called BBs. Some air rifles may also launch fin-stabilized projectiles such as darts or hollow-shaft arrows. Air rifles can be powered by different mechanisms, including spring-piston, pneumatic, and compressed gas. They are used for small game hunting, pest control, recreational shooting, and competitive sports such as the Olympic 10 m Air Rifle and 10 m Air Pistol events. When buying an air rifle, it is important to choose the right caliber for the intended purpose. For example, .177 caliber air rifles are good for plinking fun in the backyard or target shooting at distances under 50 yards, while .22 or .25 caliber options are better for shooting pests or small game, especially at distances beyond 50 yards.