 A "proof round" is an ammunition assembly designed to be used in proof testing; this can use a fixed cartridge, a semi-fixed cartridge, or separately loaded projectile, charge and primer.A "proof shot" is a special projectile used in a proof round or other projectile weapons, electromagnetic guns for example.Small arms proof rounds resemble normal cartridges, though they will typically bear special markings to prevent them from being confused for standard cartridges.