Here is a quick and easy way to get all 5 of the firefight achievements using a custom game setting called “Cheevos – Elites” that you can download from my fileshare on bungie.net. It actually comes from player Booooooyakasha who is the original creater. In a custom Firefight match, just load up the game “Cheevos – Elite” and prepare for some craziness. Easiest map to do this on is Corvette because of how small it is and you don’t need to go searching for enemies to kill. (All Elites in this match)

You’ll be able to pick up the following achievements:

• Firestarter – Scored 50,000 points in a Firefight game.
• Blaze of Glory – Scored 200,000 points in a Firefight game.
• Crowd Control – Earned a Killionaire medal in Firefight.
• Heat in the Pipe – Scored 1,000,000 points in a Firefight game.
• Game, Set, Match – Completed a Firefight set on Legendary without dying.

Additionally, if you choose a jetpack during your loadout and also find a Needler you can get:

• Lucky Me – Earned a Triple Kill while Jetpacking in Campaign, Firefight or Matchmaking.
• A Spoonful of Blamite – Killed 10 enemies in Firefight or Campaign with a supercombine explosion without dying.

One tip for this game mode. Try to find yourself either a Rocket Launcher or a Concussion Rifle in order to make the game go by a lot faster. I’m also sure you can pick up a few other achievements here for weapon usage if you didn’t already get them in campaign mode. You can also speed up the process by playing with a few friends as the scoring is team based.