If you don't want to use special ammo packs letting the ice breaker get to 6 rounds and switching to your arc sniper can yield anywhere from 6-12 rounds depending on the type. Edit: for those whining about me spreading this. When you swap between weapons it has a conversion rate for ammo. Bungie had to enter a unique conversion rate for the icebreaker( even if it's a blanket 50% ) . It is impossible they did not know this existed. If it's overpowered is another conversation but they already know. This isn't a exploit or glitch it is LITERALLY JUST SWAPPING WEAPONS and using the calculated conversation rate Bungie programmed in. PS. To those of you who know it's a good thing to spread helpful information around the community thanks. Have a great week and may all your nightfall loot be what you wanted.