The most efficient way to gain this achievement is on the level "The Pillar of Autumn" on Legendary difficulty (To gain the other achievements if you haven't already)
1) Bandana (Infinite ammo)
2) Boom ( 2x explosive damage/radius)
3) Famine (Less ammo dropped by enemies) - Cancelled out due to Bandana.
While going for this on Legendary you should refrain from picking up Overshields
and Health Packs
so that you may simultaneously achieve these as well: