actually i believe it is possible, i think i saw it in another mod...but you only get 2 frames.
You mean that Vibrating Gun on one of those futuristic mods? That was done using a modified fire-graphic for that weapon so that there was an edited barrel of the gun on it, as well as the fire-flash, and a slightly elongated barrel on the actual gun. Very clever idea, whoever's that was.
Anyway, I do not mind the idea, and I would like a rotating barrel on the Minigun while firing or the pump-thingy for the Spas-12 to move after a shot. I support, as long as it will not take too long to implement.