Make one... Have someone stick their hand about a metre infront of the barrel of the tested weapon and have a microphone a few inches from their mouth connected to a decibel metre. Pull the trigger on said weapon and judge the volume of the emitted yelp to determine if the weapon will be passed through.
In the event that you don't have access to a microphone or a decibel metre, repeat the first steps... just this time instead of listening for the scream, watch for blood. If the chronograph draws blood, the weapon is deemed unusable during the game.
Glock Glock... Who's there?