Mission: Crew Expendable
Recommended Difficulty: Recruit
Once you infiltrate the inside of the ship and find the first container yard, you'll take out a few enemies and then walk forward and an enemy will jump at you from behind cover. Kill him, and he will drop the Desert Eagle. Pick it up and use it to kill at least 5 enemies now. Just line up your shots and use your stun grenades if possible to help. The gun should come with plenty of ammo and it will usually be a 1 hit kill.