gunsmith [gunsmiths]◼◼◼(person skilled in the repair and servicing of firearms) noun [UK: ˈɡʌn.smɪθ] [US: ˈɡʌn.smɪθ]
artificer [artificers]◼◻◻(member of the military who specializes in manufacturing and repairing weapon systems) noun [UK: ɑː.ˈtɪ.fɪ.sə(r)] [US: ɑːr.ˈtɪ.fɪ.sər]