I just bought a carbon fiber, 4500 PSI, 68 cubic inch, Air tank off Ebay.
Looking to mount the tank under the barrel, ahead of the trigger guard.
Will modify or build a new regulator for the tank to acheeve 2500 PSI outlet pressure.
Will then pipe the 2500 PSI to a 5 cubic inch chamber and valve assembly that mounts where the normal AF tank mounts.
The ultamate goal is high power (70 FPE in .25 cal.), regulated pressure, and many shots. I’ll optomise the valve for 2500 PSI operation, and the length of the barrel.
The 68 cubic inch , 4500 PSI tank should provide 3 or 4 times the capacity of the standard 34 cubic inch AF tank at about the same weight.
I can pipe the regulated air to the 5 cubic inch chamber using a capillary tube (a small O.D. copper tube with a .025 inch I.D.). Sence the 5 cubic inch chamber does all the work, I can fill it slowly through the capallary tube. This small tube will be easy to route from the under-the-barrel tank to the back of the 5 cubic inch, rear mounted, regulated chamber.
Its possable to add an adjustment knob to the regulator to allow for variable power.
The beauty of this arrangement is that can be a retrofit to any AF gun. Use the AF rail system to mount the carbon fiber tank and regulator. The 5 cubic inch regulated chamber and valve just screws into the rear of the gun where the normal tank goes, then connect the two with the small capallry tube.



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Akula the offset is for forward or back on the dovetail to get the scope right where you want it. Some dovetails are to far forward and you use this to move it back. Cuda

The “offset” arrived. It’s not an offset in my book. It’s in line with the rifle. It works just fine by the way but the off set escapes me. AKULA

[quote=”baz”]blodnob, if you use bottles that size, you will need a string vest like this to carry them in.


hey baz give me the job to to carry those all day long,hahaha

MM; I’m awaiting the arrival of an offset scope mount for my Condor .22 with a Gladiator bottle cover. This scope mount gives a 3/8 inch off set from vertical to the left for the shooter. Here’s the link from eBay. http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&rd=1&item=350013842732&ssPageName=STRK:MEWN:IT&ih=022

This may help if your stock gets too large. I learned of this technique of an offset scope mount from guys that set up deer rifles from WWI .35 Remington semi-autos. The stocks and barrels of these beasts required that an off set mount for a scope be used. These rifles are just too big and nasty to mount an in line scope.

I’ll post on the effectiveness of this mounting system. And yes, I’m aware that everything I point at will have to be ajusted for. It’s the price you pay for comfort and a consistant cheek weld. AKULA

blodnob, if you use bottles that size, you will need a string vest like this to carry them in.

Your right , it would be to big on the stealth. Was looking more towards the bullpup layout i started but running at 300bar.Possibly on 9mm also.
Atb, Sean.

Cool! I didnt take it wrong. Thanks for the encouragement!.

Tank is about 4 inch diameter and 11 inches long, weighs about 2.66 pounds, including the 850 PSI paintball regulator. At least thats what I think Iam getting — have not seen it yet. Got it off Ebay. Its a “pure energy” tank. It might be too “fat” to mount behind the gun and still see through the scope.

I am using your work on the “in tank regulator” as the bassis of this project. Hope you dont mind. You proved it could be done.
My barrel volume is a little over 1 cubic inch, I may try a 4 Cubic inch regulated chamber. I’ll make it from a 6061 aluminum round, 1.25 inch OD, and .875 chamber diameter. The chamber should be good for the full 4500PSI, with a 4 to 1 safety factor. What do you think?


Hey Mark.
What are the dimensions of the bottle ? I could make use of one if one were available similair to the standard AF/GP item.

Mark; I didn’t wish to insult, I wished to enjoin in your vision. I think you’ve a winner of a project and I’d like to see more of it.

I was a paint baller once…when I had a step son. I made sure he enjoyed the experience of combat at its lightest. I can only remember bruises. Some pretty severe. Then again, I’ve never seen anyone shot through with a paint ball. That’s a different matter all together! AKULA


The paintball people have been taking advantage of 4500 PSI tanks for a while now.
Why cant we do the same with PCP guns?
The tank was only $150 delivered – new tank, not used.
I’am not Mad, just got another 3 months of winter to kill!


Mark; You’re a mad man. With this said, build at least two of your systems. I’ll buy one and others will be there to envy your work. Please post as the work progresses! AKULA

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