QB79 Ninja - The $200 PCP

[sr1sws]

Can someone give me a link to the ninja reg that can be adjusted up to 3K? All I can find is up to 1100 or 850. I don't see anything anywhere that says you can order them adjustable to 3K.

I hope you aren't thinking of running a QB at 3000psi, that would be dangerous.

+1

I would not want to be anywhere near that "experiment".

Steve

[Airsnipe]

Don't worry, I don't plan on using this reg for anything. Just curious. I was just wondering about it's use as a PCP reg at around 1800psi. But this brings up the question, what if the seals failed in the reg and it was not regulating properly and pressurized to full pressure of the tank? So that would be a hazard? You all don't think the reg is built well enough to handle the pressures if something went wrong? I don't know much about these regs so would have no idea. Again, just curious.

[huklbery]

Don't worry, I don't plan on using this reg for anything. Just curious. But this brings up the question, what if the seals failed in the reg and it was not regulating properly and pressurized to full pressure of the tank? So that would be a hazard? You all don't think the reg is built well enough to handle the pressures if something went wrong? I don't know much about these regs so would have no idea. Again, just curious. 

The exhaust side has a 1.8k burst disc, for those experimenting with pressures beyond this has to be changed out obviously.  The truth is a ninja bottle is perhaps the safest way to enjoy HPA. 

[sr1sws]

Don't worry, I don't plan on using this reg for anything. Just curious. I was just wondering about it's use as a PCP reg at around 1800psi. But this brings up the question, what if the seals failed in the reg and it was not regulating properly and pressurized to full pressure of the tank? So that would be a hazard? You all don't think the reg is built well enough to handle the pressures if something went wrong? I don't know much about these regs so would have no idea. Again, just curious.

That's why there's a "low pressure" burst disk.  As supplied, it's an 1800 psi version (1.8k).  That's what protects you and the gun if the regulator fails.

Steve

[Ribbonstone]

If it has a 1.8K burst disk on the regulated side, it will blow that disk and vent the air.  Not too unusual for a 1.4 to 1.5K output to blow the 1.8K disk with a bit of use.  If you change the 1.8K for a 3K, you could well have a gun failure.


How would it fail?

Depends on how well the tank is attached to the rifle.  Standard QB79 tank block would likely sear screws and detach with the HPA tank like an air powered rocket. Some of the reverse bottle conversions would have the knurled color holding the standard end cap (or bulk fill end cap) onto the tube, which I'd also suspect of searing and ending up with the same type of air powered rocket.

No one really knows the strength of a QB co2 tube.  If the end cap/tank block mounting held, then either the air tub would be strong but soft, and just swell up...if hard and brittle, then likely to crack and release air pressure all at once (the more dangerous of the two).  Of course, it could hold that 3K air just fine, but as you'd likely NOT have enough striker strength to open the valve (valve lock) would be stuck trying to get the air out.

[pllagunos]

So if we could get a 2k disk it should work fine with 1800psi right? I remember reading that the 1.8k disc actually blows in 1.5k because it was designed to fail below the stated pressure

[nervoustrigger]

Unfortunately there are no off-the-shelf burst disks between 1.8k and 3k that anyone here has ever found.

[pllagunos]

So how do you regulate to 1.5k without the disc failing?

[nervoustrigger]

In my experience, 1500psi is about as high as you can go before the 1.8k burst disk ruptures.  Occasionally a disk may fail at slightly less than that.

On occasion I've made my own burst diaphragms but it's not something I'm inclined to recommend to others.

[rsterne]

1500 psi is usually OK, but sometimes will fail after some time when the burst disc fatigues.... It really is a bit of a lottery when/if it goes.... At 1400 psi I have never had one fail.... At 1600 I have had them fail immediately and others last for years (ie still in service without issue).... It really depends on the tolerance on the 1.8K disc you end up with.... Good idea to buy a few for spares....

Bob

[Ribbonstone]

All you'll find in burst disks today are 1.8K, 3K, 5K, and 7.5K.  Way back in the day, they were not all one piece (which is why they are sometimes called "unified" or promoted as "one piece"...'casue it wasn't always that what...but I guess it's like old stores with signs promiting they have airconditioning...we forget it wasn't always so), and some industrial applications are still two piece (a vented plug and a round wafer of specific pressure metal).

 Back to the original posters urge for a 12 foot pound HPA conversion.  Have tried it both ways, with a lot of tuning in between.  Can get a QB adjusted to 12 foot pounds running on 1500psi air.  Gives you 1500psi of air to work with (3K to 1.5K).  By moving more volume, can get to 12 foot pounds with 800psi air.  Gives you 2200psi to work with (3K to 800pis). EITHER way can work for a 12 foot pound .177.

BUT... If 12 foot pounds is still the goal, it's a WHOLE LOT easier to get there with 800psi as that is closer to the intended pressure function of the valve. Takes fewer mods to the co2 system running on 800-850psi air to get to about the same shot count and the same energy per shot as when running on 1200-1500psi air.

[BigTinBoat]

BUT... If 12 foot pounds is still the goal, it's a WHOLE LOT easier to get there with 800psi as that is closer to the intended pressure function of the valve. Takes fewer mods to the co2 system running on 800-850psi air to get to about the same shot count and the same energy per shot as when running on 1200-1500psi air.

Plus the ES will be less, at least in my experience. While testing different power levels at 1500psi my ES was much lower at a 18-19FPE tune then it was at 12-14FPE. At 18FPE I am seeing single digit ES while shooting in the 900fps range. When shooting at 600-700 range I was seeing a 20-25FPS variance. That equates to less than 1% vs over 3%. Finding the "balance" between FPE and PSI is generally best.

High power on lower pressure = lower efficiency
Lower power on higher pressure = lower consistency

[WECSOG]

Thanks for the comments. Another advantage is that a standard 850 psi tank/reg combo is cheaper and easier to find.
Btw Ribbonstone, it's a .22 unless they accidentally send me a .177. In that case I might just keep it, but probably not.

[Ribbonstone]

Actually. found I could get more 12 foot pound shots in .22 than in .177 so you should be good for a whole lot of shots.

[WECSOG]

Well, my QB arrived and it looks good! However, it is my Christmas present so I have to wait until Christmas before I can play with it! I did check to see if my 9 oz co2 bottle would fit under the barrel. It won't, which I expected.

After all this talk of running it on 850 psi, I saw a Ninja SHP Pro V2 1100 psi tank/reg on Amazon and ordered it. So I guess that is what I will start out with, at least. However, I have a 2260 tube and JDS block that will need a regged tank too, so I might still get an 850 setup for the 79, at some point. I really do want max shot count with this gun, while having approximately the performance of my Benji 392 at 8 pumps.

[huklbery]

Well, my QB arrived and it looks good! However, it is my Christmas present so I have to wait until Christmas before I can play with it! I did check to see if my 9 oz co2 bottle would fit under the barrel. It won't, which I expected.

After all this talk of running it on 850 psi, I saw a Ninja SHP Pro V2 1100 psi tank/reg on Amazon and ordered it. So I guess that is what I will start out with, at least. However, I have a 2260 tube and JDS block that will need a regged tank too, so I might still get an 850 setup for the 79, at some point. I really do want max shot count with this gun, while having approximately the performance of my Benji 392 at 8 pumps.

I have another Ninja bottle on an AS 392.  I used a AS to paintball adapter and then the offset adapter that he shall not be named offers.  The AS offers scope groves as well like the limited edition did.

[WECSOG]

What kinda performance do you get from your AS 392?

[Tweeter]

My new qb79 barrel seems to shoot great, under .5" groups at 20 yards so far with JSB 18.1's but when I took it back apart to smooth out the breech slot that the bolt rides in I noticed that the bore is collecting some lead.  None of my other barrels do this.  Would it benefit from a good polishing with jb bore paste?  I think maybe the rifling edges are too sharp.

[wiffle32]

I've got a boatload of paintball gear - including several HPA tanks (70ci, 2x 68ci, and a 13ci Ninja) - two of my tanks are regulated to 550-600psi for paintball guns, and two of my tanks are using 800-850psi outputs. My 72ci tank has an adjustable regulator up to 1200psi.

My question is - should I aggressively pursue PCP using my current air sources?

My 13ci/3k Ninja seems like a prime candidate if I employ a lighter hammer spring for the 800psi output. The larger tanks could easily be harnessed with a coiled remote line used to supply air to the valve chamber on any PCP.

This method of air supply could reduce my PCP investment significantly.

[Tweeter]

You can pick up a Qb79 from aurgun depot for around $100 and just pop the tank on and shoot.  They are very simple to work on as well.  If you do go the Qb route you may want to tear it down and smooth everything out, lots of info online for the how to.