Gatling Gun for Transformers Prime Beast Hunters Voyager Class Optimus Prime. I add a version that can be printed piece by piece (they need to be glued), including a rotating barrel and two more without moving parts: one as a full piece and the other in 4 parts, with the top and barrel pieces apart in order to make the job easier.
As the title says, it's meant for the Voyager Class BH Prime (and it can be stored on its back). I don't own other scales of the figure, but you could try to fit it if you want, just consider that the peg for the hand's grip is 5 mm in diameter for this scale.