More fun with QB79s ... 12g cartiride adaptor

[Dukemeister]

I have been running my QB79 .177 off a "refillable" 88g cartridge. I bought a 12g adapter off the bay for a few bucks, tried it out today:
101_2528.jpg101_2529.jpg

I got 24 good shots (on target at 40ft); I shot one 12 shot group that was 1/4" high and about 3/8" o/o; the next 12 shot group was right on the dot, about the same size, then the last 3 went low. I waited 20s between shots.
Pretty good for 1 cartridge.

[pharoah007]

how do you refill it?

Ebay #?

[Dukemeister]

how do you refill it?

Ebay #?

The 88g has a one way Foster in the end:
P1020581.jpg90g CO2.JPGNipple.jpg
Good thing I read this, senior's moment I put the 88g empty in the freezer to chill. LOL.
I have bought a lot of paintball accessories from this dude:
http://www.ebay.ca/itm/New-Quick-Cha...item3f21351cd0

[AirGunEric]

Here's one not made in China:

http://scopesandammo.com/storefront/...-adapter-p-743

[pharoah007]

Nice.

Sorry for all the Newb questions....how does one fill these (via the Foster valve) ?

Is there a inexpensive way to get HPA into them? I have seen a hand pump (looks like a bike pump) but it was not cheap.

[AirGunEric]

Another tank (i.e a SCUBA or SCBA tank) and a hose, or a pump and a hose- and yes, a very good pump is just under $300.00, a cheaper Benjamin pump is available for a bit under $200.00. You can also get smaller tanks/bottles (i.e. 48ci or 68ci) that you could walk into a paintball place and have filled easily enough (most paintball places now fill 3000psi HPA tanks).

[Dukemeister]

Nice.

Sorry for all the Newb questions....how does one fill these (via the Foster valve) ?

Is there a inexpensive way to get HPA into them? I have seen a hand pump (looks like a bike pump) but it was not cheap.

Yes, filling is the same as you would bulk fill any QB/AR CO2 gun.
The 88g cylinder is only for CO2, it doesn't work well with HPA because there is no regulator. If you want to run a QB79 on HPA, one economical way is to get a 13 ci 3000 psi HPA tank regulated at 800-850 psi and hook it in directly to the tank block. You need one 2" or less in diameter or else a dropper block is needed for the tank to clear the barrel. Alternatively, a larger HPA tank 48 or 62 ci can be tethered to a paintball ASA-Foster fitting in the QB79. Many paintball ASA-Foster coiled hoses come with all the fittings.

It would be relatively easy to hand pump a 13 ci HPA tank to 3000 psi. It is quite a workout to do a 48 ci tank. But it can be done! (I have done it many times now... saved a whopping $48 in fill fees alone, and have paid for the pump rebuild kit to boot), but my pump(s) are holding up.

On a related note, I have added a BN rubber o-ring between the valve and hammer on all my QBs - it's supposed to work as a debouncer, and save gas. I have found shot to shot consistency is pretty good, but I haven't measured what, if any, decrease in gas consumption there is. Speeds decreased up to 100fps with the O-ring installed, I had to adjust other parameters to maintain non-PAL speed with CO2.

[pharoah007]

I came across a end cap for the stock pressure tube that had a fill nipple and a PSI gauge in it.
Can one simply pressurize the stock pressure tube with HPA?

What is the safe PSI range inside the stock pressure tube? How much PSI does 2 standard CO2 containers generate?

Thanks.

[AirGunEric]

1500-1600psi is all that would be advised on a stock tube- and about all a stock QB valve can handle before locking up. Co2 pressure is not affected by "volume"- i.e. 2 caplets vs. one caplet does not give any higher pressure- it's maximum pressure is determined by how much it can expand- which is affected by temperature- the higher the temperature the higher the pressure.

At around 130* Fahrenheit, Co2 expands enough to be around 1800psi- the typical burst disc pressure on a Co2 bottle, so anything less put into a stock Co2 tube should be fine- although there is no guarantee of this, it has proven to be a reasonable estimate and many people have used 1600psi on the tubes without issues.

[Dukemeister]

I came across a end cap for the stock pressure tube that had a fill nipple and a PSI gauge in it.
Can one simply pressurize the stock pressure tube with HPA?

What is the safe PSI range inside the stock pressure tube? How much PSI does 2 standard CO2 containers generate?

Thanks.

It looks like a bulk fill adapter with a gauge. It isn't a regulator.
Although you *can* fill it with up to 1600 psi air (risky), your every shot will shoot slower than the previous one.
If you want to bulk fill, stick with CO2, which is self regulating, or attach a regulated paintball HPA tank.
There is a thread over on the (cough) other forum about filling the QB series from a SCUBA tank - don't even think about it.