I am lucky enough to have two exotic weapons. Naturally you can only equip one at a time. My
Gjallarhorn rocket launcher is leveled quite a bit and my
Suros Regime auto rifle is new. With a heavy ammo synthesis module I can swap out my Suros and equip the Gjallarhorn when I need it. Swapping out weapons normally eats up ammo, but using a module solves that problem. I can quickly use five rockets and switch back to my other exotic.
Gjallarhorn Rocket Launcher: Solving problems 1000 Glimmer at a time. Especially triple Armored Minotaur spawns several levels higher than yourself. If I end up doing a Raid when they open I will be well stocked with modules.