It's not the rarest. The drop rate for the hawkmoon and Monte carlo are lower because bungie are Xbox fans. They want to make sure the PS exclusive weapons are mostly only in theory because 99.9% if PS users don't have this weapon even after over 1500 hours of play. Bungie is secretly working for Microsoft to Screw over Sony by saying "hey here are exclusive" but lolsonydumbasses almost nobody can get them. Trollololol.