Lyman's extremely popular A-Zoom Snap Caps are the best choice for safety training, function testing and dry firing practice. Their rugged design has proven to withstand thousands of dry fires while still protecting the firing pin. One drawback with dry firing snap caps however is when they are used in striker fire type pistols. These firearms require that the slide be drawn back to cock the pistol, which then extracts and ejects the snap cap from the pistol. New StrikerCaps solve this problem! StrikerCaps are made without a rim and are equipped with a centering O-ring which grips the chamber walls and keeps the snap cap in place in the chamber. Once it is chambered, simply rack the slide to cock the pistol. StrikerCaps will absorb the firing pin hit just like standard A-Zooms, however will stay in place for quicker, easier dry fire practice.