Both Barrels

Both Barrels is an achievement for Halo: Reach multiplayer matchmaking that will be made available for DLC playlists with the release of the Noble Map Pack. The achievement is earned by earning a double kill with the shotgun. It is represented by two crossed shotguns over a Double Kill icon.

Trivia
The title is a reference to a similar challenge in Call of Duty: Modern Warfare 2 where the player must empty "both barrels" of two Ranger into a single enemy.