After the success of the AR25 Mk4 ISC, it was deemed a plausible route to take for a heavy-duty combat-shotgun. A fellow named "Nathan Hawker" was leading up the R&D team at Johnson Arms Company at the time and essentially created ninety percent of the M28 MK2 "Hawker"'s design material. The "Hawker" is a ten-gauge box magazine fed beast. It's "buck" is slightly more conventional, albeit hexagonal and made out of tungsten/titanium alloy fused with a copper/tin alloy allowing for immense penetration and tight grouping due to the weight of load. The box magazine holds a total of twenty shells, and the weapon does have an adjustable choke should the need for tighter grouping prove appropriate in the field, and of course, the R&D team pushed for a recoil reducing buffer-tube in the stock. Many infantrymen of the NAF simply refer to the "Hawker" as the "Can-Opener". A term that garners respect and fear, the fear especially so after the Siege of Torbruk where it proved itself as a valuable weapon against the Kaizerreichs Stahl-Korp. A slug is yet to be developed, but many of the "Hawker"'s R&D team are pushing for a dedicated model firing a sharpened armor-piercing magnum-slug.
Amazingly, said secondary program did prove successful and produce a viable slug-rifle for NAF troops: [link]