A revolver is a hand-held projectile firearm using a chemical reaction to propel a lead pellet. Revolvers are characterized as handguns and derive their name from a rotating cylinder that moves the next loaded chamber in to firing position when the hammer is moved back to the cocked position.
Fred Noonan used a revolver to hold the Voyager away team hostage after he and seven other Humans are awakened from a 400 year stasis. (VOY: "The 37's")