REVOLVER

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.

RIB

A raised surface used as a sighting plane. Ribs may be either solid or ventilated. See Ventilated Rib.

RIFLE

A firearm having spiral features in the bore to impart spin to a single projectile and designed to be fired from the shoulder.

RIFLING

Any type of spiral internal bore feature of the barrel wall that imparts spin on the projectile for the purpose of stabilizing it in flight. This may be a series of lands and grooves, polygonal, hexagonal, or other configurations.