Canadian Airgun Forum

So I was pondering over how to streamline my shot string and increase shot count. I came up with this;

I like to modify the butt stock to accommodate a 48/3000 tank and adjust the regulator to 1400 psi. Now, I'm told the maximum these can be shimmed to is 1200 psi. Can anyone verify this? The burst disk is set to 1800 psi, so I have some play room.
Essentially, I would like to turn the tube into a regulated reservoir without adding an internal regulator and reducing the air capacity. I don't mind adding a little weight to the gun or turning it into a freak show....it's what I do.
Also, I'd like to replace the end plug to accommodate a feed line, thus eliminating the pressure gauge. Won't have any need for it once the mod is complete. Anyone have the means to machine one of these? Ultimately, I'd like to replace the whole tube with an aluminum version. With the increased weight at the back and decreased weight at the front, it should balance itself out.

Any constructive feedback is welcome and greatly appreciated.

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The flaw with experience is, it causes us to forget what we were like when we didn't have any.

Most of the common 48/3000 paintball tanks with an 850 psi output use a coil spring and won't go over about 1000 psi.... If you change to a Belleville stack, you can safely go up to about 1500 psi without blowing your 1.8K burst disc.... You may get away with 1600 or you may not.... and even if you do, filling it in your house and then putting it in a hot car.... or just many fills and refills fatiguing the disc.... and it may burst.... If it does, make sure you have a change of underwear handy....

Bob

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Dominion Marksman Silver Shield - 5890 x 6000 in 1976, and downhill ever since!
Airsonal; Too many! Springers, Pumpers, CO2, but I love my PCPs and developing them!
Proud Member of the 2000+fps Club!

Thank you, Bob. Please define Belleville stack. Is this purchased or made?
What if I were to make a burst disk that would never burst? These are intended to protect the device they are powering, but the tube can handle much more than the reg can put out. Would this not render the burst disk moot?

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The flaw with experience is, it causes us to forget what we were like when we didn't have any.

The belleville stacks Bob is referring to can be referred to, in his thread:topic56198

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"The key to immortality is first living a life worth remembering."

Bruce Lee

You can get a 3K burst disc, which if you are putting the tank on an AT44 would be equivalent to the MSWP of the tube (OK, so 200 bar = 2900psi), so no problem with doing that....

You can buy Belleville washers (AKA disc springs) from McMaster Carr, Trakar, or Ninja, the size you want is 0.032" thick, 3/16" ID x 5/8" OD, and you need 12 of them plus some flat shims.... That will give you the ability to get to about 2000 psi, maybe more.... Of course the higher your setpoint, the less headroom you have in the tank, so the fewer the number of shots....

Bob

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Dominion Marksman Silver Shield - 5890 x 6000 in 1976, and downhill ever since!
Airsonal; Too many! Springers, Pumpers, CO2, but I love my PCPs and developing them!
Proud Member of the 2000+fps Club!

As for aluminum for your pressure vessel, grade 7075 which is very strong.
Aluminum has a poor fatigue cycle as compared to steel. I am pertaining to the threads that would be cut in to seal the tube as a vessel. This is something that needs to be taken into consideration thinking upon the route. JMO

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May the cry of the pack be with you upon your hunt

Whitewolf

Thanks again, this is very helpful. Can you suggest a stack config that would give me an output of roughly 1400 psi instead of using the fill, test, empty and shim method?

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The flaw with experience is, it causes us to forget what we were like when we didn't have any.

Thanks, Kim, I too wondered about this. For now, I think I will only pursue the end plug which I can tap into. While I have your attention, is this something you can machine?

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The flaw with experience is, it causes us to forget what we were like when we didn't have any.

Stack configuration depends on the brand of regulator, I can give you a rough idea for the Ninja regs....



All regs are different, you will have to experiment....

Bob

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Dominion Marksman Silver Shield - 5890 x 6000 in 1976, and downhill ever since!
Airsonal; Too many! Springers, Pumpers, CO2, but I love my PCPs and developing them!
Proud Member of the 2000+fps Club!

All regs are different, you will have to experiment....

Bob[/quote]

Bob, I took my Ninja 13/3000 apart and something just hit me. What if I were to gut the reg, replace the 1.8 burst disk with a 5k and turn this into a secondary tank? This would double my air capacity.
Can you foresee any problems with this approach?
I would use all stainless steel fittings and tubing to feed the main tube.

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The flaw with experience is, it causes us to forget what we were like when we didn't have any.

Yes, you can convert the regulator to output full pressure, but you can't just remove the piston, the O-rings are necessary to prevent the air from escaping around the bonnet joint.... You can either fit a spacer to hold the piston open, or you can remove the reg. completely and mount the tank using a 5/8"-18NF coupler instead of the ASA output on the reg.... You are correct that if you leave the reg. in place, both burst discs will need to be 5K....

Bob

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Dominion Marksman Silver Shield - 5890 x 6000 in 1976, and downhill ever since!
Airsonal; Too many! Springers, Pumpers, CO2, but I love my PCPs and developing them!
Proud Member of the 2000+fps Club!

Many thanks!

_________________
The flaw with experience is, it causes us to forget what we were like when we didn't have any.