CUP WAD

A powder and shot separator of a shallow cup design which when loaded with lips down acts to help seal powder gases and so protect the rear of the shot column.

CUT CHECKERING

Checkering which is cut with a tool into the surface, either by hand or machine, rather than impressed.

CUT CHOKE

A choke formed by a reamer during manufacture of the barrel of a shotgun.

CUT OFF RUPTURE

A generally circumferential separation in the side wall of a cartridge case. May be complete or partial.

CUT RIFLING

A process of forming the spiral grooves in the bore of a rifle barrel by a cutting tool which has a hook shape. Also called Hook Rifling.

CYCLIC RATE

The rate which a succession of movements repeats itself; in an automatic firearm, it is usually expressed in shots per minute that are theoretically possible to be fired, given an unlimited supply of ammunition.

CYCLING AN ACTION

The act of chambering a cartridge, firing the cartridge, opening the action, ejecting the spent cartridge case, and loading the next cartridge if applicable.

CYLINDER

The rotating part of a revolver that contains the cartridge chambers.

CYLINDER ALIGNMENT

The relationship of the axis of the chamber in a revolver cylinder to the axis of the bore.

CYLINDER BORE

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