This Xbox 360 controller mod will allow you to fire single fire/semi-automatic gun in Call of Duty as if they were fully automatic.
Step 1: Take Out Screws
The parts you will need are a Xbox 360 Controller, T8 Tamper Proof drill bit (found online), solder and solder wire, drill, box cutter, metal wire, and a Momentary Push Button (bought at RadioShack).
First take out the seven screws in the back of the controller. There is one screw under the barcode where the battery pack goes. Remove it with the box cutter. Use the T8 drill bit to remove the screws.
Step 2: Remove Parts
Next pull apart the controller and take out the circuit board. I removed the rumble packs to make the controller easier to put back together in the end but you can keep them in if you wish.
Step 3: Drill Hole for Button/wire Button
After you take the controller apart, hold the back piece like you would when playing and find the spot where you want the button to be on the right side. Use the drill to drill a hole for the button to go through. Next take the button and metal wire and feed the metal wire through both connectors.