Having trouble getting the 'Kill Box' achievement on "Return to Sender" in Modern Warfare 3? Here, let Ray and Michael from Achievement Hunters help you out. Oh, and the best part? This is good for the Xbox 360, PlayStation 3, and PC versions of the game. Personally, this one took me a couple tries to get, and I can only assume this gets harder on the higher difficulties. The reward for your efforts are 20G for 360 players, or a swanky bronze trophy for PS3 folks.