"In the world of spuds today"

[jackssmirkingrevenge]

Crosman 2240 big bore musings with a balanced valve:

[Gippeto]

"Tube in tube" is an interesting idea.

Maintaining stock dimensions for the most part?

[jackssmirkingrevenge]

"Tube in tube" is an interesting idea.

I figure 6061 with 1/16" wall thickness sleeved snugly inside should be more than enough for a 3000 psi working pressure.

Maintaining stock dimensions for the most part?

Yes, GGDT suggests that it should be ok for close to 500 fps for approx 75 grain 0.357" projectiles in a 6 inch barrels, though I doubt I would get more than 3 useful shots per fill. The other possibility I'm considering is adapting it for a 13 ci bottle similar to what Bob did here and using a longer barrel at approx 850 psi regulated for a larger and more consistent shot count.

[Air2theBrain]

Was just reading that article you linked Jack, can't believe the amount of shots he achieved on a single fill.

[jackssmirkingrevenge]

The trick is the use of a regulated bottle, filled to 3000 psi but with an output of 850 psi. Ninja bottles in particular have easily adjustable regulators that can be taken down to around 450 psi, something to consider for a high performance QEV+3 Way Valve repeater.

[Air2theBrain]

For sure...was just looking at regulators before. : )

[Gippeto]

The other possibility I'm considering is adapting it for a 13 ci bottle...

In the event you don't have enough ideas ( )...those with threads are intended to install into a 22xx tube.

[jackssmirkingrevenge]

That's a nice production like you got there! Does it use an empty CO2 capsule to seal?

[Gippeto]

Uses an oring to seal to the tube, so tube is pressurized and valve needs to be sealed and properly secured.

[jackssmirkingrevenge]

Presumably this is only safe for regulated HPA within the constraints of the tube that is not normally pressurized.

[Gippeto]

Co2, low pressure pcp (2000psi) or regulated. Wouldn't use or suggest using a factory 22xx tube beyond that.

Can't stress enough that valve needs to be properly secured.

http://www.airgunforum.ca/forums/topic69553.html

Walter did a hydrotest on a 2240 tube a while back, first sign of failure was associated with bearing stress on the tube wall where the valve was secured. Calculated yield strength was similar to 4130, but since we don't actually "know"...erring on the low side seems wise.

[Zeus]

ITWOST, it turns out a black square QEV (ebay special, 3/8" output, 1/2" everything else) happily handles 1700psi. Pilots rather violently too. Further testing will feature a functional chamber as opposed to a plug, probably about 100cc.

[jackssmirkingrevenge]

ITWOST, it turns out a black square QEV (ebay special, 3/8" output, 1/2" everything else) happily handles 1700psi. Pilots rather violently too.

No video to share?

[Zeus]

Video when it's more than a vapour cloud making machine Jack, it's borrrrrriiiinnnngggg. And whenever I decide to break it, I do that into a lump of fittings on the output, so it'll be no more than a thud! But first I want to find out what a AA does with 1500psi up its kiester.

By the by, it turns out I had left the (buggered) core in the schrader, when I tried to pilot it, I got the traditional sprinker valve farting noise. I think that's gotta be the highest pressure valve fart I've encountered.

And if anyone has suggestions of things for me to try to break with HPA, I'm interested to hear them. On the list so far are a variety of PVC and black poly fittings, maybe a 3/2 valve (after testing how much pressure one will work at reliably). We all know stuff like slide valves just leak or seize up. Perhaps a pneumatic cylinder too, but I'm out of ideas otherwise.

[jrrdw]

[youtube][/youtube]

Will we need ear muffs?