whenever someone uses this gun (which isn't very often) I see them use it all wrong! they try to take out many small enemies with the full auto, but this gun wasn't designed for that: step 1: run to cover, start charging, move out of cover step 2: aim in and fire at the strongest enemy in the room until they are dead step 3: repeat until just a bunch of tier 1 enemies remain. kill these with your grenades while you have pocket infinity equipped or melee, so you get more ammo for the next batch. for bosses: step 1: charge fusion rifle step 2: fire near feet step 3: hold trigger and if necessary move sights down step 4: repeat in reality: use this as if it was a rocket launcher. use it conservatively on the high level enemies until they are dead, then use primary to take down weak enemies. and the best part: when you are completely out of ammo and our on your last clip, if you are not in combat: keep holding down trigger and don't: double jump, sprint, go to ghost, switch weapons. it looks amazing