Just a thought, if you can't cast it, why not sell the file for others to 3D print, now obviously you get the risk associated with people casting the 3D print and then profiting off of said casts or passing/reselling the file. But if you price it right, you might be able to dissuade the likes who would try to do such things.
EDIT: I personally am not interested in printing a Halo 5 sniper rifle, I just had this idea when you said you wouldn't in all likelihood be casting it. Don't want to give you the wrong opinion that I'm desperately after your 3D files