Magnetic accelerator coil

Im going to try to keep this short.
So a friend and I are both sophomores at our highschool and we are both in chemistry (which is a higher level science) and i built a coilgun for last years project and attempted to build a PWM driven one this year.
My friend and I want to build a rather large coilgun using either 10 microwave oven caps or close to 40 or 50 caps from computer power supplies. What i need help on is whether we should use the microwave caps which are high voltage but low capacitance or the power supply caps which are 200 volts and around 500 micro farads.
I also need help on what wire to use for my coil and how many turns for the coil. i would like help with a coil for each cap size.
We are planning on using either a 3millimeter by 5 centimeter long steel rod or a quarter inch bolt.
our goal is to at least shoot it through the wall of the physics classroom and maybe through the door of a car.
anything helps. Thank you

Energy storage depends on the square of the capacitor voltage, so you get much more bang for your buck with a higher voltage than capacitance value.

WOrk it out by using " C x V^2/2 "

Steve