This is a simple gun that uses magnetic wire! Bassicly how it works is when you charge the six 330 volt capacitors and realease it into the magnetic wire it magnitizes it causing the nail to shoot forward and momementum keeps it going forward. Its is pretty simple and doesn't cost much.

Step 1: Supplies and Tools

Supplies
6 disposable flash cameras(two shown other four are capacitors also ask for recycled cameras a Wallgeens)
Magnetic wire(found at radioshack)
Two bottle caps with holes in them
Pen
Nail
Wire, and cardboard for the case
Tools
Pliers, tape
Philips screwdriver
Knife

Step 2: Getting Capacitors and Charging Circuit

First pry open all the disposable flash cameras so you see the chipboard. Then pick one you want as the charging circuit. Carefully take your pliers and discharge the circuit by toching both capacitor legs at the same time with the pliers(a spark should occur). Do the same with all the other flash cameras but take the capacitors out by snipping them. Remember don't snip off the capacitor on the charger circuit.

Step 3: Hooking Up the Capacitors

First snip off the flash on the charging circuit(shown in the next picture).Now you want to connect all the left legs on the capacitors and next all the right legs. Once thats done tape them all together and add another two wires at the end of the sixth capacitor.(i stacked mine but you should make a straight one, that way it is easier to connect all the left legs and all the right legs).

Step 4: Starting the Coil

First remember the length of the nail determines how long the coil should be.Also you want the tip of the nail to be just barely in the coil. Okay now take your pen and remove the ink(leave the bottom cap in). Now that you have everything lets start! Take your two bottle caps and tape them to the pen about the size of your nail. After that leave two inches off it and start to wind the magnetic wire tightly one after the other. Once you'r done with the first coil tape it up and start again backwards, whenever you finnish a layer tape it. At the end leave another two inches. You should have between five to ten layers.

Step 5: Finnishing and Firing!

Now take one of the extra wires on the capacitor and hook it up to the magnetic wire( remember to scratch off the enamel on the magnetic wires at the end). Then put your battery in the charging circuit push the button and once its stops making a whining noise or the light goes to red touch the remaining end of the magnetic wire to the other remaining wire and you should see a little spark and the nail should zoom out. I am not responsable for injuries.