CYLINDER BORE

A shotgun barrel with a uniform interior diameter forward of the forcing cone to the muzzle end of the barrel.

CYLINDER GAP

In a revolver, the space between the cylinder and the barrel measured with the cylinder in the rearmost position.

CYLINDER INDEXING

In revolver-type firearms, the rotational movement of the cylinder to bring the next chamber into alignment with the bore.

CYLINDER PIN

The pin around which the cylinder of a revolver rotates. This is a feature found on revolvers in which there is no crane. Also called Axis Pin, Base Pin, Center Pin.

CYLINDER RELEASE LATCH

A device which permits the swinging out of the cylinder from the frame of a revolver.

CYLINDER STOP

A device to stop cylinder rotation in proper alignment with the barrel in a revolver. Sometimes called a Cylinder Latch or Cylinder Bolt.

CYLINDER STOP NOTCH

One of the machined grooves on the circumference of a revolver cylinder that is engaged by the cylinder stop in order to assure barrel and chamber alignment. Also called Bolt Notch.

DAMASCUS BARREL

A barrel formed by twisting or braiding together steel and iron wires or bars. The resulting cable is then wound around a mandrel and forged into a barrel tube. Sometimes called a Laminated Barrel.

DATUM

A reference plane, point or diameter that provides a base for calculations and measurements.