Instructions
Load the Call of Duty 4 video game, and enter into normal gameplay. Choose a gun that will maximize your chance at succeeding in the map. For example, if you anticipate fighting a lot of enemies at one time, one of the many available machine guns is probably the best choice.
Empty the barrel of the gun that you choose to use by shooting it at enemy forces. The number of bullets required to empty the clip depends on the gun being used but usually ranges from six to 20 shots.
Hold the "L1" button to aim the gun once your clip has emptied itself. Simultaneously hold down the "Square" button on the controller until you hear a clicking noise and see the clip in the bottom right-hand corner of the screen reload to full capacity. Continue shooting, and repeat this process when you need more ammunition.