Many shotgun manufacturers recommend storing shotguns with the cocking springs tension let off. This can add to the functional life of the shotgun and keep it in optimum working order. Our snap caps are made with precision brass heads, which has spring loaded firing pins for the ease of tension that is released when a shotgun is fired. Snap caps are also a great tool to practice dry firing your shotgun to teach safe gun handling, improve your shooting skills and tune your trigger. Pro-Shot's quality brass snap caps have cotton mops that fit into the chamber area for chamber rust protection. Add and oil to the cotton mop such as our one step CLP /zero friction for extra rust protection in your shotgun chamber. Always remove excess oil before use.