I ran today's heroic story missions only using Coldheart (for the catalyst progress) and even if I killed Vandals only using 5 shots out of 101 in the mag i still ran out of ammo really quickly since I used ammo faster than I found more ammo (keep in mind i can kill a dreg with 2 headshot ticks, a vandal with 5 and a shank with 2 ticks) Even when I'm being super conservative and only shooting at close ranges and landing only headshots to not waste ammo i still spent most of the mission looking for every little green box i could find just to be able to shoot my gun, that's not very fun. I got like 150 per brick and that clearly wasn't enough even with only using 5 or so shots per enemy