For those of you that don't know what a coil gun is; It's basically a big coil of wire around a tube, an electromagnet basically.
When you shove a butt load of energy through it, it'll create a massive magnetic field. Now if you put a metal object inside the tube, a little bit far from the coil, the projectile will get pulled through. Then turn off the coil soon as it reaches the middle of the magnet, and it'll keep on going... really fast! This is where capacitors come in. These store a lot of energy, and shoving it out in a split second, perfect for coil guns.
Here is a HUGE one (2000 joules + )in action. Link
No I don't condone the making of weapons, but these are a lot of fun and a good learning experience, and my low level setups (65 joules)can't possibly cause damage to humans(from being shot with it that is) However, the capacitors in here, even in my EXTREMELY small gun, can kill you if you get a charge across your heart or across any other vital organ... if not, these capacitors WILL leave marks... PLEASE do the research before attempting anything of the like.
My Gun
Some of you remember my first coil gun I posted here last year. That was powered with a single 6 joule capacitor, and fired small nails about 20-30 feet.
This one uses several capacitors to make for 65 joules of energy! Which is still small, but will shoot a 1/4" by 1 inch solid iron bolt (they are quite heavy) 40-50+ feet. (see vids) I mounted 8 flash camera transformers (1.5V to 330V) in parallel which are powered by 2 D Cells. which are connected to the caps. These charge the caps in 15 seconds.
The caps are than hooked into a relay, which is hooked into the red button trigger. I hit the trigger, shoves the electricity through the coil, sling shotting the projectile through the aluminum tube.
All this is mounted onto wood, which can be shoulder fired. but I haven't covered the caps, and I don't think I want to accidentally ZAP myself.I won't get into the details of explaining everything, it'll just take to long and I doubt you'll read it.
Here are pics.
The Gun
The Projectiles
Breach Loader
And the vids are attached. Feel free to ask questions, and if you want better vids just ask.
*Proceeds to shoot other stuff*
, up to a point anyways) and use . (you bridge one of those caps with your skin... you'll be missing limbs 
) It'll run me about $200-$350 if I go through with a single coil device... even more if I go multi stage.
I believe railguns work better, but they are MUCH more complex, and require a large starting cap bank. (They also "lose" metal as when the two rails push the interconnect forward, the metal actual moves with the current, and you get a corrosion/erosion effect unless you use something like platinum or something 
