These precision shotgun snap caps are comparable in weight to standard ammunition, making them ideal for realistic function testing. They are particularly beneficial for releasing the tension on the mainspring during long-term shotgun storage. Cowboy action shooters utilize shotshell snap caps for loading and dry fire practice. Whether you require snap caps or training rounds for a side-by-side or over/under (U/O) shotgun, consider shopping at Lyman today. Designed to safely release mainspring tension during the storage of shotguns