For safety training, function testing or safely decocking without damaging the firing pin, A-Zoom training rounds are much more than conventional snap-caps. They are precision CNC machined from solid aluminum to precise cartridge dimensions, then hard anodized for ultra-smooth functioning and long life.Note: 9mm A-Zooms are NOT recommended for use in revolvers with half moon clips.WARNING: A-Zoom 22 Long Rifle Action Proving Dummy Rounds are designed to teach safe firearms handling. They are not snap caps. They may be worked through the actions of any 22 Long Rifle for function testing. Dry firing will deform the head and will limit their use to 4 or 5 hits.