The principle is sound (twist-guide rifling systems are used by some custom barrel manufactures even today) and I've seen machines similar to this in person. *************** You'd have to change the cutter geometry, admittedly, for it to be practical for PVC... a .02" per pass cut with an indexable ...

Baffles? That's a tad complex; just drop a compression spring into the chamber and make a schelkin spiral.

I doubt a wooden dowel would be smooth enough, strait enough, or uniform enough for this to work well... but the concept is sound. Perhaps one could try it with an aluminum rod.

ISP of H2-LOX rocket engeins is 530 seconds, IIRC. ... so that sets an absolute upper limit on your attempts, based on the highest velocity one can get H2-O2 exaust to go, of about mach 15. Other than that, yeah, sounds safe... actually way over built. I've seen research papers on detonation set up ...

Oh, my local hardware store carries them... and I don't mean in 9 volts.
Otherwise? Haven't seen em anywhere.

If you want the cannon to be louder in the downrange direction, you could mount a rocket nozzle downstream of the burstdisk. I don't know enough about nozzles to tell you how big to make it, but I do know that its construction can be as simple as an 11* cone. (I think that's per side, but I'm not su...

Flat plates are weak in pressure-bearing applications; overkill isn't a bad idea.

Plus, in the event of a failure, a heavy endcap will be endowed with less kinetic energy.

Forgive me if this concept has already been discussed, I don't follow the suppressor discussions as well as I should. ******************** It seems that most of the suppressor designs that people come up with are designed and function in the same manner as firearm silencers: they put a large expansi...

Eh, strength of thermoplastics increases with decreasing temperature. Period.

Besides just looking at graphs of the quality:

http://www.pipa.com.au/docs/PV008.html

and <a href="https://www.ppfahome.org/pvc/faqpvc.html">this</a> table:
I also found a table in which:
70*F = 1.04
60*F = 1.15

Vaporizing a wire and using the resulting plasma to propel projectiles isn't a new idea... the technology is termed "electrothermal".

Apparently, it looks promising for achieving very high muzzle velocities.

Well, you could make a system similar to the <a href="http://www.swivelmachine.com/html/rimfire.htm">airrow</a>. . . but you'd either have to a) Use high pressure air/CO2 or b) put up with fairly anemic performance. Numbers indicate that 300 psi air would probably be acceptable if you where firing 2...

I'd be willing to make a couple steel spudcutters and donate them to the cause. If someone would donate money for materials and/or shipping, that'd be awesome. (As a note, I'm too busy with AP English homework to make them if you just want a set. Sorry, but this is a one-time deal to the winner of a...

Found <a href="http://www.isohunt.com/torrents/?ihq=antique+rifling">this</a> on Isohunt. Thought you guys might like to know. I'm not sure about the legalities of the file; whoever planetcammed it didn't include the copyright... if there is one. It doesn't look like a professional publication... al...

1) Technically, the direction of flow in the chamber does matter; if it changes, you get a localized high-pressure region. I don't expect this to be significant in this situation. 2) Air leaves through holes for a reason: pressure. And the higher the pressure, the faster it leaves. Thus, one finds t...

Besides the properties of the reactants and products, and the difficulty of acquiring them, propane-oxygen outperforms the hydrogen-chlorine. Post-reaction pressures, starting at 1 atm and 300 k, stoichiometric mixtures, per Gaseq: H2-Cl2: 10.3 atm C3H8-O2: 18.2 atm Or for that matter. . . C3H8-air:...