Snap Caps
A snap cap is a shooting accessory device shaped like a standard cartridge or shotshell which contains no functional components. A snap cap is used to ensure that dry-firing firearms of certain designs does not cause stress and impact damage to the firing pin and/or the barrel breech. Some snap caps contain a false primer that is either spring-buffered, made of rubber or soft polymer, or none at all. The springs or plastic will absorb the impact force from the firing pin during dry-firing, allowing the user to practice trigger pull or safely test the function of the firearm action without damaging its components.