 The triple barrel shotgun is the rarest configuration, and arguably is an odd variant of a double-barreled shotgun rather than a drilling, since it lacks the rifle/shotgun combination that all the other drillings have.The triple barrel shotgun is generally laid out like a side-by-side shotgun, with the third barrel centered and below the other two.Although, the Chiappa Triple Crown has a triangular arrangement with one on top and two below.