Please don't get angry... I got this from a legendary engram that dropped randomly on a strike. It is a fantastic gun because you never have to reload it or pick up ammo (once you unlock the feature). The bad part is that green ammo is now worthless, the fantastic part is that it recharges and reloads itself automatically. You can get headshots from across Kansas and once you get used to the recoil it is very easy to control. My only regret is that I can't use the obviously chainsaw barrel to melee...