This checkoff list could be used by a scribe to keep track of which Scouts have earned which merit badges or could be used by an individual Scout.
Shotgun Shooting Merit Badge
A shotgun is a precision instrument, designed to shoot a shot charge in a specific pattern to cover a designated area at a certain distance. Unlike a rifle, the bore of the shotgun is not rifled, so the shot emerging from the muzzle is not spinning.
Printable helps for requirements:
One of the resources which BSA provides for Scouts BSA Troops is a set of troop program feature guides. Our troop is planning a shotgun shooting outing in August, so they will probably be looking at some of the ideas in the Shooting program feature.