Snap cap

Firearm accessory device

A snap cap is a firearm accessory device shaped like a standard cartridge/shotshell but contains no functional components, namely the primer, propellant (gunpowder) and projectile. It serves the same purpose as a dummy round, but different in that a dummy is usually modified from a real cartridge with its propellant and primer removed, while a snap cap has a monolithic outer shell and is specifically designed to be a fake cartridge from the very beginning.

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