Opened it in notepad, only legible thing was "created with The Gimp". I don't actually have Gimp, but this may be a lead . . .

Hmmm . . . me thinks convert it to .ogg? That could be completely wrong.

Well, since we're waiting for someone to be kind . . .
Anyone heard of Not Pron? It's a lot like this . . . but can take some more ingenuity and programs at times.

http://www.deathball.net/notpron/

I have a feeling there will be plenty of addicts on this site.

Except for RDX . . .

Anyone want to give a hint for 31? My Firefox has been open on this page for days. And I'm slowly going crazy over it.

What is "opening" the box doing? Is it referring to image editing?

Hmmm. . .

Don't have any experience with copper but anything requiring a torch is out, sadly. Parents.

Well as of now I'm thinking a 1" ball valve w/ spring trigger. Lots of flow and hopefully the spring will make the opening time a little quicker.

Eventually I'll make a metal piston valve, but ...

Wow that was fast.

Yeah thats about what I figured.

I'll look into a metal piston valve . . . and eventually post the cannon.

Thanks!

Hi! I've been away doing other things but I'm trying to start a "Kinetic Science" club (I know, a blatant euphemism) at my High School, and feel like making a new cannon just to help advertise, etc.

My basic plan was a small, rifle-like high pressure steel gun. After doing some snooping on ...

Quite a standard discussion nowadays. But has anyone actually taken the time to read the 2nd Amendment?

"A well regulated militia being necessary to the security of a free State, the right of the People to keep and bear arms shall not be infringed."

My opinion is that because of how it is ...

Well, they have been tested up to 160 psi, but NEVER try to take them up that far. It really varies by brand, so to be safe don't take it over 75.

Plenty of people will say otherwise, but for your own sake stay under 75.

Thanks!

I'll eventually get around to it but im running out of cash right now.

The marble barrel screws on to the end of the 1" barrel, so its just kinda "half breech loading".

Added piston pics, etc.

I also have a paintball barrel for it, but its not painted yet.

Well, my first professional-ish looking piston cannon is done!

Specs:
2.5" chamber . . . about 2-3 ft.
1" barrel with female adapter
Hot glue piston with a neoprene disk
Pressure Gauge
Schrader valve for filling
1/4" NPT ball valve for actuating piston
2 grips from a water gun

Mostly made of parts ...

I think that could work, but I have had a few blowguns that leak. Also, If you drop the gun or lean it against something the blowgun might open. Meters just seem sturdier and safer with ball valves.