hah okay.... for a combustion spud gun, do you presurize the fuel? WD-40 in my case. or you just spray it in and launch it?

what are pilll bottle cannons? actually made from those tiny medicine bottles? or am i missing something?

why not start with a smal hybrid and learn the hard way?

sry for such a newbish question, but how tighly does your 'ammo' have to fit in the barrel?
should it be exactly the same diameter as the barrel? or should it be slightly larger? or smaller?
do tight fits work best?

thanks

first off, i gotta say, some of the guns on this site are amazing. I'd love to make one of em but my question is how to get started... i have idea of how the system works, but how should i get started putting it together? i wanted to make a hybrid, so what kind of combustion chamber do i need? and h...