Corpser Corpse

Gears of War Hint - Corpser Corpse
When you are pitted against the Corpser in the Act 3 mines, there's a quick way to win. The Lancer's (chainsaw rifle) constant stream of fire makes it the weapon of choice here. Shoot at the belly of the Corpser, working any angle you can between its legs.
If you hit the belly a few times, it will lift it's front legs and expose it's face. Immediately fire up at it's face and chin. It will shriek and move back.
Hurry, move up grab ammo and repeat. If you don't move fast enough wretches will arrive in waves and make things ten times harder. You must hit the Corpser's face three times.
You'll back it up onto a platform with two destructable joints. They're lit up and on the ground. Shoot them both and the Corpser will plunge into the Imulsion liquid. If you're quick enough you can kill the corpser before any wretches arrive.