Some snap caps contain a spring-damped false primer, or one made of plastic, or none at all; the springs or plastic absorb force from the firing pin, allowing the user to safely test the function of the firearm without damaging its components.
Some snap caps contain a spring-damped false primer, or one made of 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.