Solder on a female threaded end then use reducing bush fittings to reduce this to a 1/8" compression fitting. Drill through the compression fitting so the bit will slide straight through then use the compression olive to hold the bit in place. That should be good enough for cork. If you can drill ce...

thermal autodecomposition becomes dominant. Then I must eat my words :) Thats from wikipedia, though I looked further and indeed found reference to it decomposing explosively under welding temperatures. I was under the mistaken impression that it was much more stable then H2O2 (which if taken as pu...

Sorry when I said "explode" I was refering to the whole thing going kablooey. Even with extremely high pressures it does take some time to push the projectile up to speed such that a lower pressure over a longer time will be better, this was the problem when nitrocellulose was first used until ways ...

N2O isn't flammable and wont decompose to any useful extent. H2O2 would in higher concentrations. But these are still firing under the same principles as any chemical propellant gun, self sustained "decomposition" could define any explosive. H2O2 with Al powder hit with a huge jolt would be interest...

Found a couple more pics on an old hard drive. And another little arrow firing piston gun, the flights slide to the back when fired, it was crap.

When I was playing around with magnets here http://www.spudfiles.com/forums/viewtop ... tml#280310 I placed a ring magnet (1" OD, 1/4" ID) around a .177 barrel. using a ball valve no matter how slow it was opened the velocity achieved was always the same (penetrating 5 drink cans at 100psi).

bighead33 wrote:.. or the cleanout cap back fires pleas post

Yep my first had a huge 6" DWV endcap with BBQ igniter stuck through it, lasted maybe 50 shots then exploded straight back into my face, split lip and bloody knuckles.

I know you asked for offline, but http://www.smallparts.com.au/store/categories/ has what you require. Including 4.53mm ID thick wall brass perfect for barrels.

I really dont see the appeal of using marbles inconsistant, light and expensive, as Jack suggested previously in this thread a bolt and nut would be a far better option. I posted chronograph results for shotshells at low pressure here http://www.spudfiles.com/forums/brass-harpoon-gun-t20581.html , i...

I have some primed cases here so I shot one around until it went off, average fps is in the 290's @ 20psi with an unmodded case and just over 600fps @ 100psi. Knocking the primer out and replacing it with a nail gave around 400fps at 100psi, chrony result is below. Thats my niece below, she attempts...

Ahhh thanks Jack they are the ones. I don't remember drawing that first one but I no doubt did, didn't think I put an O-ring in the piston maybe I drew that as an ideal picture rather then what I did but then how did I know 2" Cu fit into the bush reducer... I'll have to screw it open to find out wh...

I tried to get a movie today but this is the result, camera is very old with a tape thats been recorded over many times so quality is amiss. I could only find 1 empty shell so I thought if I started at 20psi I could get more then one shot, but alas I lost it. It was just an empty case no modificatio...

in fact it would have been posted on the old old spudtech forum 9 years ago. I think I have a diagram of it archived somewhere, I'll look it up when I get home :) True there was one I drew in paint both side and top view, and also an animated gif explaining the operation of the piston valve. The gi...

I dont know what KLM is so I'm assuming its "pipe".

Suprisingly after sitting outside under a walnut tree for many years the old girl fired up just fine today, after a few bursts of dirty water and dead spiders its good to go.

DR's ozonated peroxide enema (:/) may still be worth looking into, you can never be too careful.