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)
Skulls used:
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: