The Heavy Shotgun, the Shotgun, and the Splinter Bow were the only weapons in Nosgoth which had no variations. No founder's or unique variation of the Heavy Shotgun existed, and unlike other classes' weapons (but like other Beastmaster weapons), no Heavy Shotgun variations with visual effects had been produced by the time of the game's cancellation.
The Heavy Shotgun is referred to as "Weapon_Shotgun_Heavy" in the Nosgoth game data. Concept art portraying five Beastmaster weapons labelled it #3.