I've logged over 1300 hours playing Destiny. There is one set of ship blueprints (crypt hammer) that has never dropped, even after I started farming for it recently (opening hundreds of chests on patrol per day). I keep getting repeats of blueprints for the 8 destination treasure ships I already have. Is this normal? During the past few days I get at least one or two blueprints per day, but none of them are the one I am missing. Does the crypt hammer have a much lower drop rate? Any constructive input is appreciated