Dry Fire Without Damaging Your Firearm
Snap caps are great for dry fire practice because they let you concentrate on keeping the firearm steady during the trigger pull, which helps eliminate flinch when using live ammo. Centerfire Pistol and Rifle caps have a solid aluminum body and a spring-loaded brass "primer" that absorbs firing pin impact to prevent damage to the tip of the firing pin.
Big Book Catalog, Issue:66, Page:540
SPECS: Pistol/Rifle- Aluminum body, brass "primer"