For duty 4, us use the R700 sniper without an ACOG scope. Then I have a smoke grenade as my special, and for my perks I use, 1) Claymores 2) Stopping power 3) Iron Lungs
~Claymores are nice even if they don't kill the enemy, because they let you know if someone is trying to sneak up on you. ~with the R700, stopping power kills with one shot unless they have juggernaught on. ~Iron lungs lets you hold your breath alot longer.