Use the following trick if you are playing online or in Carrier mode. When your gun runs out of ammo you usually have to re-load, then cock your weapon. Note: This does not include RPGs, and rifle mounted grenade launchers. This trick makes it so you do not have to cock your gun after re-loading. When you run out of ammo, let your character reload, then quickly sprint forwards a short distance. Stop sprinting and return your gun to the firing position. It will be ready to fire without re-cocking.