Declassify Mission: Finish before ammo dump explodes in 5:20
This is a very straightforward section. You just need to fight your way through several locust forces. You'll encounter Loomis along the way which will help a bit. Be both careful and aggressive. Pick up the locust heavy weapons such as mulchers and boomshots to make your job easier.
Once you've reached the end point, go past it and you'll find the COG tag skull on the wall to the left. Go past it and go around the stairs to find some bloodstains on the floor. The COG tag should be there.
K. Barrick, PVT, Port Lorrence
Before proceeding, replenish your ammo and restock your weapons. There's a boss battle ahead.