Does anyone know the exact conditions for DDT of propane or acetylene?

Yay! Somebody gets what I'm trying to say.

but the voltage reg can only source one amp in most cases and when voltage is reduced current is also reduced if the wiring is keep the same (remember ohms law?)for example if i have wires that have 100ohms resistance (100 ohms is way higher than what a normal wire would have but its just an exampl...

Well the only reason I still think it might work better is that folding the pipe might make it impossible to fit the folded end into the bigger pipe.

Does steel shatter? I think the only real trouble might be finding fittings that are the correct size, just what are you using for a chamber and can it easily be fit to normal steel fittings?

This is very impressive! Could it be possible to control more than one mine with the same cell phone? You could make a network of mines, it would be great.

You should be fine if the gun can really take that much pressure.

Mr. Gopher plans to reduce the voltage of his battery to half of what it is intended to be used for, it seems like anything you try to do will get too hot after a few uses. I think the best thing to do would be to just purchase a rechargeable 9v battery. I'm not super sure about this, but wouldn't c...

Well, the only way I know of, is to have a friend stand about 100 yards downrange and shoot. If the thing hits him before he hears it, it'ss supersonic. I'm kidding! But really, without a chrony I think the only way would be to have someone stand downrange, but where you know you won't hit them. Se...

Well I would have thought he meant hydrogen except he mentioned it is cheap to get, but I think you have to make your own hydrogen which can be a pain... A problem with helium and hydrogen both is that they are easy to leak. Any tiny pinhole leak will release gas, your solvent welds and threaded fit...

Clide's way is probably the best, it would minimize impact on the pipe.

The tiny chamber gives you pretty good power, I just need to find a more narrow barrel for mine so the thing has a little accuracy.

Helium is a noble gas so it shouldn't be combustible... It would be even better than pressureized air or CO2 for pneumatics because of its light weight. You wouldn't want to use helium in a hybrid for the same reasons that you would not use CO2. Hydrogen is probably the best fuel for use in a hybrid...

I've never actually seen a good database of phase diagrams.
I've only seen them in textbooks, and they are usually phase diagrams for water like the one shown above. Do you have any good links to where we can look them up?

Wow those guns really exploded!
Nice pictures.