Now do those hundred shots in one real time minute.

haha that would be epic!

Nice! Keep up the good work and good luck with the hybrid

You cannot pressurize a sprinkler-valve actuated pneumatic cannon with a "bike pump", for example. There is too small a volume (at too slow a rate of fill) to pressurize the top of the diaphragm. - As you are pumping air into the Chamber, the air (at such a small rate of fill) simply bleeds out of ...

WOW! I know this has been said before, but french guns all look amazing for some reason
J'aime bien. C'est super cool!

Looking good. What pressure are you shooting at? And the one thing people here love to see is damage pics!!!!!
Keep up the good work

Make sure the bleed valve is closed. I'm not sure which position the switch should be but try both and see. If that doesn't work try taking it apart, cleaning it, and then putting it back together. Mine wouldn't want to seal several times because of debris in the valve.

It seems that the problem would be more of how to fill it rather than how to fire it. I would suggest flipping it around and drilling a hole through the back side. That way the projectile can shoot out and when you remove the lid of the sharpie you have direct access to the valve. Just my two cents.

Ok thank you very much. I just wanted to be sure.

I was thinking about how I would fill my copper coaxial and figured that a "T" fitting would be required, 1 port into the gun, 1 port for the blow gun, and one port for the schrader valve. When I examined the the blow gun however, I realized that the tip it came with alows me to screw in my schrader...

Or epoxy all the way

haha epoxy is really nice, but how would he change the cartriges?

@Bipyro: I'm relived to here that even 3 times my volume is manageable with a shock pump, although highly unpleasant. @saefroch: I was thinking just some wading or something, but I'll have to plan it out some more. As for simulating rounds, I can just use solidworks to get a pretty accurate predicti...

Yeah i realize this and was thinking of having a light sabot or something like that that wouldn't add too much weight. I've messed around with different masses and even at 1kg the muzzle energy is only 100.1 ft*lbs. A tenth of that, 100g still produces 98 ft*lbs so i think anything that is more mass...

Hmm... Thats interesting. Too bad I don't have access to equipment that can measure speeds like that. I guess I could just use a projectile that weighs .575g and see if it produces a sonic boom. According to GGDT it should travel at 1127 ft/s, 1ft/s higher than the speed of sound if I'm not mistaken...

Yes I though that might be the case with GGDT. I also realize that an airsoft bb isn't .5in in diameter (it would need a sabot, the weight of which I haven't factored in)

Yeah "canon" was definitely the wrong term to use haha. I was initially planing on something with a 1/4in barrel however I visited my local home depot a few days ago and found out that they only have 1/4 copper coiled up for refrigerator use. This lead me to scale it up a bit and I've decided that 1...