Halo: Reach Challenge Initiative - Shootin' and Lootin'

IF YOU'RE SHORT ON TIME, load up ONI sword base on normal, skip past all of the enemies untill you get to the garage/Hangar with the locator, then back up into the garage with the locator to get a checkpoint. Once you get it, point it at the biggest group of enemies you see and pull the trigger. Reload checkpoint as necessary. To make it faster, call in the airstrike BEFORE you get the checkpoint so it will already be active when you get the checkpoint. If done right, it will take you 3 mins.

2 game Fifefight