This one will require a bit of planning to do. Again, Pathfinder on the Greenhorn difficulty is the best mission to do this on, as it's the shortest one in the game.
As soon as you land, make sure to switch to your pistol, and proceed through the level. Be very careful with your shots though, as enemies very rarely drop pistols. Make sure to let your AI teammates lead, as they can take out just about everyone on Recruit for you. If you play through carefully, you can easily nab this and the Survivor achievement at the same time.