A-Zoom .22 WMR Action Proving Dummy Rounds, 6-Pack Warning: A-Zoom .22 WMR (Win Mag Rimfire) 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 WMR firearm for function testing. Dry firing will deform the head and will limit their use to 4 or 5 hits.