I have been restoring an older sailboat this summer. I was able to get several good ideas by looking at websites of folks who build their own, mostly from plywood. If you want something simple, which fits in the back of a truck, then I've got a link for you...
http://www.pdracer.com/

Could be. But has anyone ever observed it to be not true?

That is flawed logic my friend. Let me expose it for you...

Let's suppose I think that farting into a potato gun is better than metered propane for launching spuds the fastest or furthest. I can also concoct some rationale having ...

Really? I would expect multiple sparks to increase the perforamnce of a combustion cannon. Granted, no one has ever (as far as I know) compared one versus two versus... sparks using a consistent ammo and chrony. (Latke was using a spark strip which wouldn't be expected to behave the same as ...

Jimmy,
You got me thinking. Do you think my results are influenced by the fact that I've looked at fairly high c:b ratios? If so, do you think the effects of energy lost to heating the chamber walls is mitigated by having plenty of additional energy from a larger chamber?

If energy lost as heat to ...

Jimmy, you're the one who should be providing data, since you're making unequivocal claims. However, I'll share what I know....

The launchers I've compared are my blackhawk and my patriot. Similar chamber volumes and barrel volumes. Both have a 1.5:1 ratio so they have plenty of power. The only ...

jimmy, there is no data to support your claims. You might have all the theory in the world to back you up, but in practice, I can tell you there is no measurable difference between the old in line muzzle loader versus a coaxial.

spudblaster, look at the numbers BLB posted for a 2:1 launcher. It doesn't suck.

Right now I wish I had a link to some of Jimmy's website, or his posts on the old spudtech forums. I'll do my best impersonation....

Nothing "sucks" about a high ratio. I happen to like 1.5:1 ratios because the additional noise and muzzle flash are part of the whole enterainment package. Just a ...

You may want to consider making a launcher with an optional chamber extension. Sorta like this...
http://loose-cannon.home.mindspring.com/barrel/index_files/image014.jpg

You could pick a chamber size that works with several of your barrels that have a smaller volume, and then for larger barrels ...

Joel should shut down the spudtech forums as an April fools joke.

Ooops. Already happened.

wblteen- that is a nice sleeving job. That very nice fit makes me want to give it another try. Glad to hear the hose clamp idea works in practice. I think the idea had been tossed around before, but I don't know if anyone actually tried it until you did.

Funny how folks that have actually tried ...

Those water jugs hold us to pressure spikes very well. Ever seen them dropped when full of water? The times I've seen a full one hit the kitchen floor at work, they bounce like a ball! I don't know how much pressure is generated, but it's 5gal of water falling approx a meter.

I'd be more concerned ...

You might consider making it an unembelished tube pattern recoilless cannon.

That is... projectile in one end, bag of water (or similar) in the other, fuel-air mixture in the middle.

Solves two major problems at once: fittings (because you don't need 'em) and recoil (because there is... almost ...

Banging the piss out of pipe? That sounds kinda....funny! :lol:

Anywho, you should give it a try. It only took me about 20 min for a 6 ft barrel. Plus it's a great stress reliever! And a workout!

BTW, one of these days soon I'll be testing one of those molded barrels. Just waiting for the weather ...

DR, your barrels are very nice. Can I purchase one of those fancy barrels at my local hardware store?

No?

Well then, you have the answer to your question.

People sleeve a GB barrel for the same reasons they build their own spudguns instead of ordering them from any number of websites. I think ...