alright, i know it is a big pain in the ass to have to go out and buy some stupid chip to rapid fire mod your controler. it takes time to ship and is expensive and complicated but i will show you how to do it without the chip. disclamer: i am not at all resposible for you breaking your equipment or bieng banned from xbox live. or hurting yourself somehow.
things you need
momentary push button
small flathead or torx t8 screwdriver
pencil tip soldering iron
rosin core solder
some sort of wire (mine came off a broken charger but 12 gauge is the best)
i bought every thing i needed for this at radio shack.
Step 1: Taking Apart
alright i know that going out and buying things is annoying so if you want this to be the easiest you can buy a torx t8 security proof screwdriver. i personaly use a flathead and broke the pins out of the middle of the star shaped screws. second there are seven screws. if you think there are only six you my friend are wrong. behind the battery pack it should be near if not under some sort of sticker. it is relitivly but also important. after that is done you could tape your buttons or if you are like me and cant find tape just turn it upside down and be careful. make shure the metal coils that touch the battery arent getting caught on the bottom case of the controler. when you are pulling the controler should be upside down. take the lb and rb buttons off for now all of those wires in the pictures arent going to be there because this controler is highly modified by a friend i just asked to take a picture so i could make this instructable.
Step 2: The Begining of the End
alright now that your controler is sucsesfully open you will have some circut board that looks like the shape of the controler. it will have two things dangling off of it. those are called rumble packs. there purpose in life is to make your controler vibrate to simulate what your games images are. the one on the right side is going to have to come off for your button to have clearence space. do not drill your hole too high or else it will not allow space for your button.
after you have removed the right rumble pack and have the circut board in hand it is time to break out the old soldering iron. you are going to need a pencil tip unless you are very skilled with soldering because the point you solder is less than a centimeter from points that you must not touch in both instances of soldering first take your wire and get 2 diferent wires by cutting. then strip both ends bare of the rubber coat. solder one side of each wire to the two points on the button.
Step 4: Gets a Little Tricky
alright there is going to be three dots running verticaly and near where you took the rumble pack off there are going to be 2 points horizontaly. the way you test wich points work is you put the board back in the back case turn on you box and controler and then touch the wires to the points and push the button. then after finding the points (for the standard microsoft controler it is usualy the middle point on the vertical dots and the right point on the horizontal dots. solder the points by heating up the iron put a little solder (so it doesnt stick to what you are soldering) and then put a tiny drop of solder on the wire touching the point. and do the same for the other point.
Step 5: Final Preperation
now you have to drill a hole out of the back to mount your button. dont drill to high or else the circut board will not sit back in flat and that is a huge problem. then there will be a nut on your button. take your button push it through the hole and put the nut on the end and twist untill tight. then put the controler back by putting the d pad and button pad and buttons back on. make shure they are straight or they will not function. then put the pads back on with the black dots facing up. then put the top of the controler back on and the rb and lb strip and put your screws back in with the same driver you took them out with. this mod works on all first person shooters that i know of. i also use it on gta and saints row.
now you are done! kill your friends without them knowing how you are doing it. when you push the button a pistol turns into a machine gun and sprays bullets as fast as the game allows! tons of fun