Glossary of Airgun Terms

Term Definition
Adjustable objective The front part of a scope that can be rotated to focus the scope at different distances.
Airgun A gun (rifle or handgun) that launches projectiles by means of compressed air or other gas such as carbon dioxide.
Airsoft The term applied to a type of airgun that fires spherical projectiles of 6mm diameter at low velocity. These guns are also known as air soft or softair.
AirSource® The Crosman name applied to the large cylinder that holds 88 grams of CO2.
Automatic A type of gun that fires as long as the trigger is held back (also called full automatic).
Ballistic Coefficient a number that describes the ability of a projectile to retain its velocity when passing through air.
BB A round projectile made of metal or plastic.
Blow back The action that occurs when part of the action of a gun moves to the rear as the gun is fired.
Break action A type of airgun that is cocked by pulling the barrel downward which moves a piston backward against a spring contained inside the receiver.
Caliber The internal diameter of a gun barrel.
Carbon dioxide A gas that can be contained within a cylinder and then released to launch projectiles.
Chamber The rear section of the barrel where the pellet or BB is held prior to firing.
Choked barrel A barrel that has a slightly tapered bore near the muzzle to assure that the pellet fits tightly as it leaves the bore.
CO2 Cartridge or Cylinder A pressurized container holding carbon dioxide (CO2) used to power certain airguns.
Elevation The adjustment that controls the vertical movement of projectiles on the target.
ePCP A type of high-powered airgun which has a cylinder that is charged with enough compressed air to fire several shots and maintain the same velocity regardless of air pressure using an electronic valve
Eyepiece The part of a scope sight that is placed nearest the eye.
Eye relief The distance between the eyepiece of a scope and the eye of the shooter when proper viewing is obtained.
Fiber optic A colored plastic rod that appears to glow at the ends when the rod is illuminated.
Grooves The channels that form the lower portions of the rifling within a barrel.
Group The pattern made by a series of projectiles striking a target.
Hollow point A projectile that has a hole or indentation in the point.
Kinetic energy The energy that a moving object possesses as a result of its motion.
Lands The ridges that are present between the grooves in a rifled barrel.
Laser sight A sight that projects a laser beam.
Line of sight The straight line that exists between the shooter's eye and the aiming point on the target.
Midrange trajectory The deviation between the path of a projectile and the line of sight at a distance half way to the target.
Minute of angle The distance that represents one minute of angular measure (which is very slightly more than one inch at a distance of 100 yards).
Multipump A type of airgun that is charged by performing a series of pumping strokes.
Muzzle The extreme front end of the barrel of a gun.
Objective The front lens of a scope sight.
Peep (aperture) sight A type of sight that has a small opening through which the shooter looks at the front sight and target.
Pellet A projectile (usually made of lead) that is fired from an airgun.
Point of impact The point on the target where projectiles strike (which is not always at the aim point).
Powerlet® The name given by Crosman to the cylinders that hold 12 grams of carbon dioxide.
Precharged pneumatic A type of high-powered airgun which has a cylinder that is charged with enough compressed air to fire several shots.
Red dot sight An optical sight in which a red dot is projected on to a lens that can then be aligned with the target.
Reticule The aiming device (usually a crosshair of some type) inside a scope which permits it to be aligned accurately on a target.
Revolver A type of handgun that holds a series of projectiles in a cylinder that rotates to align each projectile with the barrel.
Rifling The spiral pattern made by the lands and grooves inside a barrel which imparts a spin to the projectile as it moves in the bore.
Semiautomatic A type of gun (handgun or long gun) that requires only pulling the trigger for each successive shot.
Trajectory The curved path followed by a projectile after it leaves the muzzle.
Two-stage trigger A trigger that requires some backward motion before the actual firing motion is achieved.
Velocity Rate at which a projectile is moving (distance per unit time).
Wadcutter A type of pellet that has a flat front end.
Windage The lateral (left or right) adjustment of the point of impact of projectiles on a target.