It's been a while since i posted a cannon ! i wanted to build a nice combustion cannon, without any other features. So here it is, a simple combustion cannon, nothing fancy...
Specs:
chamber : 4" x 2'
barrel : 2" x 3'
Ignition : standard piezo-electric BBQ lighter
A couple of friends and me shot it this evening on a lake, i must admit i wasn't expecting that much noise; the thing was extremely loud, i'd say as much as a 12 gauge. It's the first spudgun of this size that i make, the recoil is impressive too: the cannon managed to slip 20cm through my hands. We managed to shoot a golf ball out of sight, all across the lake that is about 150 meters long. The potato chunk went straight over it too.
I am the happy owner of a casio exilim EX-F1 that is well known now for it's slow-motion capabilities. Be sure that i will upload dozens of carnage videos ranging from 300 fps recording to 1200 fps. That will give me a pretty accurate estimation of the muzzle velocity of the projectiles I shoot.
We did find that nivea deodorant works great, better than axe; half a second of spray is enough to make a good deflagration. When burnt clean(dry fire for example) it makes a clear blue flame, when fired with a projectile, the flame is more "conical" and yellow-red.
The only thing i would have to say is a negative point on my cannon, is that there is no serviceable cap...
here are the pics, videos to come.
well, until tomorow, have some nice time 
of combustion.There won't be any chamber fan,propane injection NOTHING just the essentials.
