Totally Worth It - 50 Points: Earn a Double Kill from the Grave in multiplayer Matchmaking.

Both Barrels - 50 Points: Earn a Double Kill with the shotgun in multiplayer Matchmaking.

Cross-Mappin' - 50 Points: Kill a player at long range with the DMR in a matchmade Slayer game.

You Ate All the Chips - 42 Points: Collect all of the flags in a matchmade Stockpile game.

You Blew It Up! - 13 Points: Blow up the research facility in a matchmade Invasion game on Breakpoint.

Poppin' & Lockin' - 25 Points: Destroy a vehicle using Armor Lock in a matchmade game.

Offensive Driver - 20 Points: Earn a kill in a matchmade Rocket Race game.
Wow, these are some terrible achievements.