Hidden weapons on The Pillar of Autumn
From Halopedia, the Halo wiki
Template:Ratings Hidden Weapons on The Pillar of Autumn is an easter egg on the Halo: Reach campaign level The Pillar of Autumn.
Walkthrough
Begin the level at Rally Point Bravo, titled "Keyes". Once you get to the first flight of stairs leading to the final area, turn immediately to your left and go toward the small building. Walk along the left side of the building until the gray material stops; turn right and melee the wall. A supply drop box containing four DMRs and one Shotgun should pop out of the wall and land on the ground. If this doesn't happen then it might have already come out by itself and disappeared due to a loading point.