Letter: R

A firearm, usually a handgun, with a cylinder having several chambers so arranged as to rotate around an axis and be discharged successively by the same firing mechanism through a common barrel.

Part used to move a breech bolt to rear.

The aiming reference seen when looking through a telescopic sight.

The replacement of one stock with another.

A circumferential bulge in a barrel typically caused by firing into an obstructed bore. See also Bulged Barrel.

A cartridge having a rimmed or flanged head that is larger in diameter than the body of the case. May be either rimfire or centerfire.

A centerfire cartridge whose case head is of the same diameter as the body and having a groove turned forward of the head to provide the extraction surface.

A type of primer found in the circumferential cavity or rim of rimfire ammunition. Usable only with rimfire guns. See Centerfire Primer.

A rimmed cartridge design in which the rim is formed with a cavity to contain the priming mix.

A counterbore in the rear end of a chamber or bolt face to support the head of a rimmed cartridge.