WhatEverHD shows how to shoot your javelin using a turret in modern warfare 2. This is made possible by using a glitch in the system that allows you to use the turret as a mechanism of projecting your javelin. You can walk up to the turret, zoom in and do what is instructed in the video to throw the javelin. The video states that the only advantage of this method over the normal javelin shooting is that you have a turret to use it on and thus the javelin travels a longer distance. You need to have ammunition for this to work.