@ jrrdw: That's not an unreasonable suggestion, but in my case, such things are actually fairly obnoxiously priced in limey-land. It's just not the type of thing that's in demand (at least if you want a front/back pair - there are some front bead versions out there for shotguns). Plus, HEAL was alre...

I can't comment on anything quite that cheap, as I spent a little more than that - about £12, which is still a very budget model, but it's a fairly robust metal one and at least so far it's seemed to be fairly well suited to the task (and much more convenient than trying to build and calibrate prope...

Well, I've finally got around to completing the work on HEAL's stock and sight mount (and got her a proper storage case)... IMG_3434_1600.jpg ... which I'd like to think is something of an improvement over what she looked like 10 years ago . You may notice that I've mounted a unmagnified red-dot the...

the diverter type of valve In all honesty, I see nothing about the "diverter valve" which would lead me to classify it as something other than a piston valve. Pistons don't have a dictated shape, size or weight - they just can't, unlike in the similar diaphragm valve, be attached to the valve body ...

I have nothing in mind numbers wise Well, if you've got any significant distance you may want to reach, knowing that would be a good start as it's then possible to work out a minimum velocity (assuming that you want a relatively flat trajectory, no more than a couple of degrees of elevation) and es...

Will propane survive 75x without auto-igniting or liquefying the propane? Larda ran Hygac20 at 200x, so I'm going to say yes. The partial pressure at 75x isn't enough to liquefy propane (depending on temperature, that happens at around 220x), and the concern with auto-ignition is gas temperature (a...

wyz2285 wrote:hard for a nob

Well that's something not to search on the internet.

Won't work... projectile CG is ahead of the fins, so the projectile will likely tip forward in the barrel and destroy itself. Trust me... ... or I could trust the real-world results. :P [youtube]https://youtu.be/5HrPNdbwqw0[/youtube] The fins are a tight fit in the barrel, and naturally align the p...

I thought HS was only possible with high velocity rifle bullets, not low velocity homemade airguns. Water is incompressible at any velocity. That's why belly-flopping stings quite so much. Certainly, a high velocity rifle bullet will cause a greater pressure spike when it impacts the water (enough ...

I mainly want to aim for range and accuracy. Do you have specific numbers? I've got a on-and-mostly-off project to achieve something similar with a 20mm calibre pneumatic. The original objective was to be able to hit and penetrate a 40cm diameter 6mm mild steel plate at 400 metres (equivalent to on...

Hydraulic fittings are commonly rated to 8,000-10,000 psi, that would be the "sane" limit to me I'd advise against it. Air starts doing very weird things at those pressures, both in terms of how it interacts with other materials and how it behaves on its own. A litre of air in that pressure range s...

Should I modify sprinkler to a dual valve for more efficiency? That's probably redundant, as the flexible hose is probably as much of a bottleneck in the system. Is there a way to INCREASE noise? Looking for a good report. Is there a way to increase recoil? Looking for the realism all the way here....

because any launcher that is powered by fuel that is extracted from petroleum is illegal in my city Well, things like deodorant and hairspray burn because they use butane to pressurize the can (or sometimes, don't burn, because some brands don't use butane), so if you're concerned about that, it co...

Oxy hydrogen is the same thing as H2 + O2... You can make it from water. Not however the same as H2O2, which would be hydrogen peroxide. ... which is indeed itself used as a rocket fuel. With the right catalyst, its decomposition rate is approximately "WHOOSHKAFROOGLEAAAARRRRGGGGHHHHIAMLITERALLYONF...

The configuration you have there, if I've read the intent of your diagram right, cannot fire, as the QEV is incorrectly connected. I'd recommend looking at the piston valves explanation topic , as QEVs work on the same principle as barrel sealing valves. The approximately volume of the air tank is T...