A-Zoom Snap Caps - Ideal for releasing mainspring tension when storing shotgunsThese precision shotgun snap caps are similar in weight to standard ammunition, ideal for realistic function testing. These are especially useful for releasing the tension on the mainspring for long-term storage of your shotgun. Cowboy shooters use shotshell snap caps for loading and dry fire practice. Training rounds are the same size as actual ammunition A-Zoom Training Rounds load in a magazine just like real ammo Teach Safe Loading and Unloading