I have all the guns I could want and my vault barely reaches the 3rd line... My characters all hold whichever weapons I'll want/need to use on each, but I would like a 3rd icebreaker so my warlock and Titan don't need to share... But I have to say, if you need more vault space, you're a hoarder and need to let go of some of your shittier weapons. Just think 'will I ever use this?' And if the answer is anything but a definite yes dismantle it (yes even exotics)