Caliber

Nominal bore diameter of a gun. Can be expressed in decimal inches (such as .22 caliber) or in millimeters (such as 5.56 mm).

Calorie

The unit of heat required to raise the temperature of 1 gram of water by 1 °C.

Canister

Small package of smokeless powder or black powder, typically in 1-pound, 4-pound, 5-pound, and 8-pound sizes, suitable for hand-loading and muzzle-loading purposes. The package is typically lightweight fiber or plastic construction, designed to vent quickly and prevent pressure buildup if accidentally ignited.

Cartridge-actuated device (CAD)

A self-contained device employing smokeless powder or black powder as the primary source of working gas to drive a piston to do mechanical work. Examples include air-bag-inflation devices, bomb-ejection cartridges, cable cutters, fire-extinguishing systems, parachute-release mechanisms, flight-recorder-ejection systems, and aircraft-seat-ejection units.

Centerfire

A type of small arms ammunition that uses a replaceable primer in the base of the cartridge.

Centralite

Generic name for a family of chemical stabilizers (for nitrocellulose) developed in Germany at the Central War Laboratory near Berlin about 1906.

Coincident gamma-ray emitter

A radioactive material that, upon decay, simultaneously releases two gamma rays, thereby making it detectable by use of several counters with coincident decision logic.

Combustion

A self-sustained chemical reaction with the evolution of heat and flame, proceeding at a controlled rate at considerably less than the speed of sound in the reacting medium, as opposed to the supersonic shock wave of detonation.

Commercial explosive

An explosive designed, produced, and used for commercial or industrial applications rather than for military purposes.

Comminution

The process of reducing the size of solid materials to a fine powder or dust through milling or crushing.

Compatibility

Lack of chemical reaction between a foreign material and an energetic material at elevated temperature. Normally measured by such thermal stability tests as Differential Scanning Calorimeter, Taliani Heat Test, and Vacuum Stability Test.