A gun including a barrel assembly feed (19) for advancing a plurality of barrel assemblies (14) of the type having a plurality of projectiles stacked axially within each barrel assembly (30) together with discrete selectively ignitable propellant charges for propelling the projectiles from each barrel assembly (30), the plurality of barrel assemblies (14) being linked together in spaced apart parallel relationship (15) and locating one or more barrel assemblies (30) in a firing station wherein the firing station operatively supports the one or more barrel assemblies (30), the gun further including a charge initiator associated with the firing station for selectively initiating said discrete selectively ignitable propellant charges of one or more barrel assemblies (30) operatively supported by the firing station. The barrel assembly (30), has an inner barrel (32) made of a hard, non-deformable material and an outer casing (33) of a ductile material. The outer casing may be deformed by the slots (20) and sprocket teeth (21) of a sprocket drive.