Those guns aren't configured like the one in game though are they? That's just the stock, the one in game also has a shortened barrel, a perforated metal barrel shroud, under and side rails, and an aftermarket magazine pull. The various parts of it exist, but I've never seen them combined in that pattern in any other piece of media. The weapon is clearly directly taken from the Division which isn't too surprising when you look at this guys other images.
