GTA

All Springer/NP/PCP Air Gun Discussion General => "Bob and Lloyds Workshop" => Topic started by: rsterne on July 15, 2013, 06:13:09 PM

Title: QB79 Ninja - The $200 PCP
Post by: rsterne on July 15, 2013, 06:13:09 PM
This thread will be slightly different than most of mine, in that it is about building a very simple yet efficient PCP for about $200.... You won't need any special tools, and there are only two things to purchase:

An Industry Brand QB79 Airgun
A Ninja 13CI/3000 psi tank with an SHP Pro Regulator

What you end up with is a gun that looks like this.... It weighs 6 lb. 10 oz. and balances right on the foregrip....

(http://i378.photobucket.com/albums/oo221/rsterne/QB%20on%20HPA/IMG_3576_zps67faf8fb.jpg) (http://s378.photobucket.com/user/rsterne/media/QB%20on%20HPA/IMG_3576_zps67faf8fb.jpg.html)

and shoots like this.... In fact twice that many shots on a full tank....

(http://i378.photobucket.com/albums/oo221/rsterne/QB%20on%20HPA/QBNinjaStock_zps190c9263.jpg) (http://s378.photobucket.com/user/rsterne/media/QB%20on%20HPA/QBNinjaStock_zps190c9263.jpg.html)

The average velocity while above the regulator setpoint was 609 fps with Crosman 14.3 gr. CPHP pellets, which works out to 11.8 FPE.... On a 3000 psi fill, it works out to 135 shots and refilling at 1100 psi.... for an efficiency of 0.95 FPE/CI....

What does it take to accomplish this great combination?.... Would you believe mount the tank on the gun, fill it with air and start shooting?.... First a little history.... The QB79 is the "tanker" version of the QB78, which was developed from the Crosman 160, and manufactured in China.... It is available for between $100-$120, and is intended to use a CO2 Paintball tank, although many people substitute Paintball HPA setups instead.... So what did I do that was different?.... Instead of the commonly available 13 CI / 3000 psi tanks that have a regulated output of 800-850 psi, I used Ninja Paintballs new SHP Pro version.... The "SHP" stands for "super high pressure" (advertised at 1100 psi) and the "Pro" refers to their "360* twist technology" which allows the tank to be rotated so that the fill nipple and gauge don't interfere with the barrel.... I recently reviewed the SHP Pro, which lists for $80 US, here.... http://www.gatewaytoairguns.org/GTA/index.php?topic=49648.0 (http://www.gatewaytoairguns.org/GTA/index.php?topic=49648.0)

OK, so the QB79 is designed for CO2, but we're running 1100 psi, what about safety?.... What people forget is that CO2, while having a nominal pressure of 850 psi at 70*F, can produce pressures as high as 1900 psi at 120*F.... At 90*F, it's about 1200 psi, and at 100*F about 1400.... and we don't hear of QB79's exploding on a hot day.... About all that happens is that when it gets hot, the velocity drops, because the hammer spring peaks out at about 1100-1200 psi.... Having said that, there are a couple of recommendations I have on the QB79, whether on HPA or on CO2....

Don't remove the action from the stock with gas in the gun.... There are two additional stock screws that thread into the tank block and provide an additional safety measure should the other screws yield....

Don't remove the breech with gas in the gun.... The valve is only secured with one screw, but sits against a steel block.... That steel block is secured on the bottom by the stock locating stud and on top by the flathead screw in the breech, located under the barrel.... ALL THREE SCREWS must be in place and tight before the gun is pressurized....

The Ninja SHP Pro regulator is equipped with two burst discs, one to protect the tank from overfilling, and the other to prevent the output pressure from rising about 1800 psi.... This is ideal for our purposes, as those pressures can be reached in a CO2 system, and in fact CO2 tanks are rated at 1800 psi.... As long as you don't disturb the 1.8K downstream burst disc, your QB79 should be just as safe as running on CO2, IMO.... I chose the SHP because of its 1100 psi output (my tanks actually measured at 1200).... Remember I mentioned earlier that the hammer spring in a QB peaks at about that pressure?.... That means that the gun should be shooting pretty efficiently without having to change it.... If you are only running 800-850 psi the hammer strike is actually too strong, and the gun will be wasting air, and may experence hammer bounce.... It still might get lots of shots, but clipping a coil of two off the hammer spring would improve the shot count even further....

Please note, I made NO modifications to the gun in any way.... I did disassemble the breech and deburr it and the bolt and the rear section of the main tube, and I polished up the trigger and hammer and installed a lighter trigger spring and 2-stage plunger.... but those are all fine-tuning details that anyone might do to a CO2 version and have nothing to do with the performance, only functioning and shooting enjoyment.... You have to slide out the barrel to rotate the tank to install it, as the gauge and fill fitting won't clear.... but that gives you the opportunity to deburr the forward section of the breech so it doesn't keep shredding the O-rings anyway....

I think this conbination of the QB79 and the Nnija SHP Pro setup is just about perfect as an introduction to PCPs.... The price is certainly right, and the platform can be modified to your heart's content.... The target style AR2079 version isn't a lot more money, and the conversion process is identical.... IMO, the QB79 and the Ninja SHP Pro go together like bread and butter.... and just in case you might be interested in spicing up that combo a bit, stay tuned as I have a couple of simple mods in order as well....

Bob

Additional information, March 2015....

Recently one of our GTA members, Ribbonstone, noticed a slight bulging of the end of the tube on his QB79, in the thin area adjacent to the screw holes for securing the tank block.... The gun was operated for a time at 1250 psi.... In response, I have done an analysis of the tank block attachment, which is detailed in this thread....

http://www.gatewaytoairguns.org/GTA/index.php?topic=105712. (http://www.gatewaytoairguns.org/GTA/index.php?topic=105712.)

If you are building a QB79 HPA conversion of any kind, you should read that thread.... If you are using more pressure than the 1100 psi factory setting for a Ninja SHP regulator, I am now recommending that you pin the tank block with two additional 4mm or 8-32 screws, or a 5/32" shear pin, between the O-rings.... If you want to be more conservative, you might want to pin the block when using the SHP regulator.... or even with a standard 850 psi Paintball regulator.... Complete information is in that thread....

Bob
Title: Re: QB79 Ninja - The $200 PCP
Post by: Mebits on July 15, 2013, 07:55:57 PM
I did exactly this, but had Mike Melick give me a tune for more power. When I got it, it was shooting pellets on CO2 at 686-723fps. When I did the conversion you describe, I was shooting 14.36 JSB's at 800 fps and getting 60 shots.

The best part? I can shoot one hole groups at 20 yds and paintballs are no problem at 40 yds. I've hit very small targets at more than 50 yards and I really have no idea what the maximum effective range is.

M
Title: Re: QB79 Ninja - The $200 PCP
Post by: supertech77 on July 15, 2013, 08:03:25 PM
great post bob,very informative ' can't wait for the next post on those mod's   ;D  thanks
Title: Re: QB79 Ninja - The $200 PCP
Post by: Ribbonstone on July 15, 2013, 08:33:41 PM
Bob, you should be the spokesman for this, make a very good argument for the QB79/HPA system and I’ve nothing to argue about.

With shipping included, will be right at $200.  For air use, might be the best introduction to air.

Tank (the custom ones will cost more…this one is ready to go at 1100psi):
http://www.ebay.com/itm/Ninja-Aluminum-HPA-Tank-13-3000-PRO-SHP-REG-1100-PSI-/171066094922#vi-content (http://www.ebay.com/itm/Ninja-Aluminum-HPA-Tank-13-3000-PRO-SHP-REG-1100-PSI-/171066094922#vi-content)

(I’ll let ya’ll know if it really comes at 1100psi…ordered one to up-grade a 5mm QB HPA conversion.)

I’ll list a few other things that might not be obvious:

1. The ones converted to HPA use very seldom have valve stem issues.  May &^^& out tomorrow, but at least one of them has run for 4 years on an issue valve valve (did remove the fiber filter, but they tend to shed/disintergrate with co2 use too). Am guessing that with the HPA tank being a closed system (doesn’t have to be opened to refill) and air being filtered/cleaner than co2, the valve stem doesn’t get sliced as often as when using co2.

2. HPA tanks are really slightly under 2”.  Common 9oz. co2 tanks are slightly over 2” (some of the heavy old-school steel tanks are under 2”).  Means HPA tanks are much more likely to fit under the barrel without contact.

3. HPA tankers are generally a bit lighter than the same gun running on co2.  Why? The weight of the co2 tank AND the weight of the liquid co2 inside the tank.

4.  Regulated air is EASIER to tune for.  No need to think of the valve self regulating over a pressure range, the valve sees the same pressure all the time.  Keep that in mind if you have the urge to fiddle with striker spring tension.

5. My serious hunting happens in cool/cold weather.  Co2 isn’t at it’s best when there is frost on the ground and ice in the water.  Air doesn’t really care.

6. May not make a difference to many, but when you are done, have a gun made of wood and metal.  The only plastic parts would be the seals. 
Title: Re: QB79 Ninja - The $200 PCP
Post by: rsterne on July 15, 2013, 08:43:19 PM
You're bang on with all those comments.... It might be possible to squeek out a slightly more efficient combination of power and shot count by fiddling with the spring preload.... but since the QB hammer setup is so close to ideal at 1100-1200 psi the gains SHOULD be small.... and maybe not worth the bother.... If you stick with 800-850 psi, it's probably worthwhile detuning a bit to stretch the shot count.... I'm planning on two stages of mods.... Upper (post valve) airflow for Stage 1.... Lower (pre valve) airflow for Stage 2.... For Stage 1, you don't even need to pull the valve from the gun, basically all you need is a set of numbered drills and a needle file.... Stay tuned!....

Bob
Title: Re: QB79 Ninja - The $200 PCP
Post by: Ribbonstone on July 15, 2013, 09:10:10 PM
Getting away from simple.  QB79 works great with the standard spring, standard striker, and a 1000-1200 psi HPA tank. 


Are ways to get mo' power, but for the average guy, the above would be a good point to start.  Even with no mods, usually see 8 -12% increase in speed simply because air is "thinner" and flows better than co2.

Now I cannot help but to pass one complication on: they are harder to get sealed with air than co2.  Does seem co2 slightly "swells" the o-rings, which helps seal co2. Air is thinner and does not swell cheap (Chinese) o-rings, so air often does have a slow leak.  Most of the time it's the gas block 0-ring(s).

SOME fit and seal just fine, holding air for as long as you'd care to measure.  Others have been real SOB's. Have used several ways to cure that, but for the guy with no lathe and looking for simple, this way has worked.

Bad news is that it takes a WEEK (7 days). Airgunners are NOT noted for their patience.

Get the bare gas block in your hands, with o-rings removed.
Degrease the "shank" (the part that fits into the air tube).
Plug the air vent and both mounting screw holes (can plug them with Al foil).
PAINT the shank with top grade varnish (like the best grade they'd use on boat decks).
Let it dry/cure 3 days.
Paint it again.
Let it dry 3 days
Take out the plugs, put on the o-rings, install (careful not to slice the o-rings when passing over the tube holes for mounting).

It's not much, two thin coats of dry varnish, but it seems to make enough difference to seal the gas block o-rings.

BTW: in my climate, tend to pull the trap door to the attic, and hang the part to dry from the rafters above the central air/central heat unit.  Is a vented attic, so it's warm and dry...pretty good paint box. BUT, it seems some varnish has a liking to UV, so for at least one day, will let it hang where direct sunlight can strike it for at least a couple of hours.
Title: Re: QB79 Ninja - The $200 PCP
Post by: PackingHeat on July 15, 2013, 10:28:31 PM
This combo is exactly how my QB addiction began. Throw in a valve tune and it is a deal that can't be beat.
Title: Re: QB79 Ninja - The $200 PCP
Post by: bradyman1 on July 15, 2013, 11:55:05 PM
Great post Bob. I have been thinking about one of these qb guns for a while.
Title: Re: QB79 Ninja - The $200 PCP
Post by: pyroboy33 on July 16, 2013, 01:40:39 AM
This is way cool Bob... ;D. I'll be honest 90% of the time your posts are waaaayyy over my head. But this mod looks like something that I might actually look into  8). Much respect for taking the time to figure this out and share your results with the rest of us.
                                                                           Cheers
                                                                                       -Caleb C.
Title: Re: QB79 Ninja - The $200 PCP
Post by: rsterne on July 16, 2013, 02:20:18 AM
Today I removed the barrel and breech to ease the restrictions and increase the airflow.... I did NOT remove the valve from the gun, all mods were made to the barrel and bolt only, plus I installed a larger transfer port seal, from a Crosman Disco/22XX/13XX.... just the rubber seal only, not the metal sleeve.... I got that idea from Tim at Mac1, and it really works great, doing a perfect job of sealing the curved valve to the curved breech, and it's larger than you can go on the porting on a .22 cal barrel....

I drilled out the barrel port one number drill at a time, starting with the #28 (0.140") and ending with the #20 (0.161").... That makes the transfer port 75% of the bore diameter, which is as large as you dare go without creating loading problems for the pellet.... The area for the airflow is a third larger than stock.... I then drilled the nose of the flow-through bolt out one size at a time, starting from the #34 (0.111") and also ending at the #20, so that it was the same size as the barrel port.... That greatly enlarged the hole in the bottom of the bolt where the air flows through, and I used a 1/8" ball grinder tip in a Dremel to smooth and enlarge the slot formed until it was the same area as well.... After careful deburring of the inside of the barrel and bolt using a needle file, I reassembled the top end of the rifle and tested it again.... Here are the results....

(http://i378.photobucket.com/albums/oo221/rsterne/QB%20on%20HPA/QBNinjaStage1_zpsd5b28c54.jpg) (http://s378.photobucket.com/user/rsterne/media/QB%20on%20HPA/QBNinjaStage1_zpsd5b28c54.jpg.html)

The average velocity while on reg. jumped up to 738 fps (17.3 FPE), giving 48 shots starting at 2000 psi before the velocity dropped below 730, and a total of 58 shooting down to 1000 psi.... That works out to 17 psi per shot, and an efficiency of 1.10 FPE/CI.... Starting from 3000 psi, you should get 105 shots down to just under 1200 psi.... This mild mannered gun is beginning to show some real promise.... The Stage 1 mods to accomplish it can all be done with a set of numbered drills and a needle file, plus a rubber seal.... and without removing the valve from the gun....

For the next round, however, I will be pulling the valve out to improve the airflow into the valve, and provide more volume between the regulator and the valve to increase the average pressure available during the shot cycle.... I'm really looking forward to seeing the results....

Bob
Title: Re: QB79 Ninja - The $200 PCP
Post by: Joe A. on July 16, 2013, 03:24:36 AM
hmmm i just might go this route for my first pcp all though ive also been looking at the bs50/51 from mike
but just over 200? now thats a price you cant beat gonna do some serious thinking now lol
Title: Re: QB79 Ninja - The $200 PCP
Post by: Kailua on July 16, 2013, 03:41:21 AM
This is way cool Bob... ;D. I'll be honest 90% of the time your posts are waaaayyy over my head. But this mod looks like something that I might actually look into  8). Much respect for taking the time to figure this out and share your results with the rest of us.
                                                                           Cheers
                                                                                       -Caleb C.

X2
Title: Re: QB79 Ninja - The $200 PCP
Post by: Bruce on July 16, 2013, 09:13:37 AM
Awesome Job! I keep thinking I might do this with my son qb78. Currently running the remote 48ci tank is fine but be nice to have it more compact.

I figure tank block and 13ci or 22ci tank with 1400psi reg. The gun already has a lighter striker and is setup for 850psi air and 18.1 jsb's start at 709fps and end up at 699fps at about 1000psi were I stopped. I do not have a shot count as I cheated... I fired several stings at the begging and then let air out of the tank to test the lower end. So quiet also at that power level! At 780fps was getting noisy!!!!!

These are great little shooters! Amazing value for the $$$

Bruce
Title: Re: QB79 Ninja - The $200 PCP
Post by: Mebits on July 16, 2013, 10:27:47 AM
It's just impressive to watch Bob work.
Title: Re: QB79 Ninja - The $200 PCP
Post by: willbird on July 16, 2013, 01:32:07 PM
And I think if I have it figured out right, if you stepped up to the better Ninja regulator, the one that can be ordered 250 psi to 3000 psi you would add about another 40 bucks BUT you would have a regulator that could be run higher than 1100 for some projects. And if you wanted to run it in a carbon fiber 4500 tank for tethered use it would be good to go too.

NINJAREG45X MSRP 98.95

It is just a tad longer than the SHP. Of course the SHP you have a larger marketplace to shop in and that $40 difference might grow a bit in a smaller market. If it is a different thread size and will not swap in with the SHP I apologize for my ignorance in advance.

Bill

Title: Re: QB79 Ninja - The $200 PCP
Post by: willbird on July 16, 2013, 01:42:04 PM
When I first started shooting as a kid we used the rifle that one is copied from, or a very similar one. I still remember the low velocity shot and ssssssssssssssss when the co2 ran dry in the middle of your string :-).

I bet they are STILL using those same rifles for that class if I had to guess.

Bill
Title: Re: QB79 Ninja - The $200 PCP
Post by: rsterne on July 16, 2013, 02:15:28 PM
Based on previous experience, where I got a significant gain on a 32 FPE QB78 running at 1600 psi, I cut off the flow-through bolt probe, squared off the end of the bolt flush with the back of the barrel port, drilled the bolt and installed a 3/32" diameter extended probe that is 0.10" longer than the original flow-through (because it pushes up inside the skirt).... Whereas on the previous time I did this mod I gained 32 fps, this time I lost 5 fps.... However, the ES seems slightly less (ie fewer high velocity shots).... The only explanation I have for this, is that on the more powerful, higher pressure version, where flow is more important, the thin probe is better.... However, on this version, running lower pressure and half the air volume through it, there is very little difference, and it isn't worth having to use a lathe to make the change to the bolt, simply drilling it out works just as well.... When I increase the power further, I would expect the thin, extended probe to work better, but of course I can't go back and test the flow-through now, all future testing will be with the 3/32" diameter probe....

Basically, either drilling out the flow-through nose.... or replacing it with an extended probe.... work equally well at this pressure (1200 psi) and power level (17 FPE)....

Bill, if you check out my thread on the SHP Pro in the PCP Support Gate, you will note that you can run it at 1500 psi quite easily.... Since anything higher than that won't allow you to use the 1.8K burst disc, which is critical to a safe HPA installation in the QB79.... I don't see the point in purchasing a more expensive reg for this gun.... Increasing the pressure past 1200 psi will require you to increase the hammer spring preload as well, or the velocity will start to drop....
 
Bob
Title: Re: QB79 Ninja - The $200 PCP
Post by: Froggy. on July 16, 2013, 05:10:38 PM
Bob, I'm also converting a qb79 to HPA...I'm considering cutting the valve +- 1/4 inch from the o ring and then to fit a valve spring to the front of the valve stem...this will increase the plenum significantly.
Title: Re: QB79 Ninja - The $200 PCP
Post by: rsterne on July 16, 2013, 06:05:31 PM
Way ahead of you.... I suggested that on another Forum 2 months ago, and my gun is currently apart and the epoxy on the 1/4" threaded spacer is hardening as I type this.... I'll have some photos likely tomorrow.... I can tell you that I measured the shoulder that the O-ring sits on, and it's the proper size (9/16") for a #113 O-ring to simply sit in a groove and seal normally, without having to tighten the two halves of the valve together.... There is a long enough threaded portion on the front valve half to get two 1/4" long rings from one valve, incidently (eg. enough for 2 valves).... I epoxied it in place with the correct gap for a #113 O-ring to be stretched into place and will then just slide the rear half of the valve into the tube....

The front half of the valve, with spring, sleeve, washer, piercing pin, and filter is no longer needed.... I will turn a spring seat on the poppet and either drill or install a spring seat on the tank block and simply use a longer spring.... The resulting plenum will be MUCH larger, with unrestricted flow into the valve seat area.... Stay tuned, as this is my "Stage 2" tune....

Bob
Title: Re: QB79 Ninja - The $200 PCP
Post by: NinjaPaintballRay on July 16, 2013, 06:09:27 PM
This is way cool Bob... ;D. I'll be honest 90% of the time your posts are waaaayyy over my head. But this mod looks like something that I might actually look into  8). Much respect for taking the time to figure this out and share your results with the rest of us.
                                                                           Cheers
                                                                                       -Caleb C.

X2

X3.  Bob is a genius when it comes to high pressure air applications. 

Bob, thank you so much for doing this review and posting your results.  I'm speaking with several QB owners including @SSS$$$ (^&$@_=s) and his new QB78 and QB79 repeaters he's releasing.  He thinks this will be a perfect solution to overcome the issues of falling muzzle velocity with rapid firing that takes place with CO2.

Very interested to see what else you come up with :)

EDIT-  ODD - I typed the gentleman's name and company name on the post but I have a feeling this forum isnt fond of him.
Title: Re: QB79 Ninja - The $200 PCP
Post by: rsterne on July 16, 2013, 07:03:26 PM
It's a great solution for the QB79 because it's a bolt on deal.... Any of the available mods that work on CO2 will also work with this setup, returning even higher performance.... You can do the same thing with a QB78, but you have to shorten the tube, drill it for the tank block, and ideally inlet the stock to add the two front stock screws as well for extra strength.... That places it beyond the ability of many, and I'm hoping that with my idea of eliminating most of the valve on the QB79 (in Stage 2) that the performance difference between them on HPA will shrink.... It's already a non-issue on a stock gun, or with my "Stage 1" tune.... only the more powerful tunes show up the difference to any degree anyway....

Bob
Title: Re: QB79 Ninja - The $200 PCP
Post by: Ribbonstone on July 16, 2013, 09:21:56 PM
Two-part text:

Sanity reasserts itself.  The 2nd, 3rd, 4th, and 5th tanker I tried HATES contact between the bottle and the barrel.
http://www.gatewaytoairguns.org/GTA/index.php?topic=49855.0 (http://www.gatewaytoairguns.org/GTA/index.php?topic=49855.0)

That one gun, one barrel, seems to stand alone in preferring contact.  Don’t know what exactly to make of that, but am going to do what the barrel/test targets tell me it needs.

I feel a bit relieved.  The world is round, gravity works, and MOST guns/barrels resent hard contact with air vessels.

Part 2: QB 78 owners:

Lets say you already have a QB 78 and are reasonably handy with hand tools (no machine tools required), can still join in the fun.

If you can do a little DIY, can convert it to HPA. 

Need a gas block.

The current standard QB gas block has changed a little bit, taking 4 o-rings rather than two.  Not real sure how that helps, as ONE o-ring that works right will do the job.

Follow this tutorial for tube cutting and gas block attachment:
http://www.gatewaytoairguns.org/GTA/index.php?action=post;msg=472273;topic=49871.0 (http://www.gatewaytoairguns.org/GTA/index.php?action=post;msg=472273;topic=49871.0)


End up with a long tubed QB79.

Here is a short-tubed HPA 79 and a long tubed HPA 78.  These two are my "hook'em" guns. Likely to be tanken out to family gatherings, picknics, etc where i can "hook" newbie shooters.

(http://i157.photobucket.com/albums/t50/ribbonstone/QB%20mods/66abe7cd-9483-483f-ab7f-091467bdff34.jpg) (http://s157.photobucket.com/user/ribbonstone/media/QB%20mods/66abe7cd-9483-483f-ab7f-091467bdff34.jpg.html)


Now Rsterne can tell you about the advantages for making power of a large amount of air “on deck” (air that is already regulated and just waiting to push your pellet.  If you have visions of high power, can either extensively mod the valve of a QB79 to gain some of that on-deck air or can convert a Qb78 and do less extensive valve mods.

If you consider the cost of a used QB you already have to be about $60.

QB gas block $35 (which would be fine for running at 1100psi or under)
JDS gas block $55 (which I would recommend for +1200psi output)
Ninja 1100psi tank = $80

Plus and afternoon of sweat.

OR if you have to buy new, call it $205…but you’ll have to ship from 3 different places so that would considerably up the cost though shipping.

But if you have a QB78 in hand, can consider that as “already paid” and think in terms of  “$105 to make it HPA”.

Lets look at it in the simplest way:

If you have 45 cc’s of on deck air volume, and you shoot one shot, finding the air pressure has dropped form 1100 to 600psi, then the NET push was 850psi.  If you have 90cc’s volume and after one shot, the pressure dropped to 850psi, then your net push was  977psi. 

Title: Re: QB79 Ninja - The $200 PCP
Post by: rsterne on July 16, 2013, 09:32:04 PM
Here is a photo of the valve I will be installing for my "Stage 2" mods.... The 1/4" wide aluminum ring is all that is left of the front part....

(http://i378.photobucket.com/albums/oo221/rsterne/QB%20on%20HPA/IMG_3578_zps463d6db8.jpg) (http://s378.photobucket.com/user/rsterne/media/QB%20on%20HPA/IMG_3578_zps463d6db8.jpg.html)

It was epoxied onto the rear portion using a #113 O-ring for a spacer (just touching).... When the JB Weld was 4 hours old (not sticky but not hard) I cut the O-ring and peeled it out of the groove and then cleaned up the front of the groove with a razor blade to remove any excess epoxy.... Once hardened, I will turn it around and face off and bore out the inside to increase flow into the poppet seat....

Bob
Title: Re: QB79 Ninja - The $200 PCP
Post by: Ribbonstone on July 16, 2013, 10:45:31 PM
 like the simplicity of the HPA QB's, long or short tubes.  Easy to take apart, change what you want or fix what is not right.  If simplicity is a virtue, then these are honorable guns.
Title: Re: QB79 Ninja - The $200 PCP
Post by: rsterne on July 18, 2013, 12:05:17 AM
I did some more work on the Stage 2 "Maxi-Valve" today.... The concept is to turn all the volume between the valve seat and the QB79 tank block into usuable valve volume.... Here are the results....

(http://i378.photobucket.com/albums/oo221/rsterne/QB%20on%20HPA/IMG_3580_zpsc6c60154.jpg) (http://s378.photobucket.com/user/rsterne/media/QB%20on%20HPA/IMG_3580_zpsc6c60154.jpg.html)

I machined a 0.10" long spring seat into the end of the poppet to fit the stock QB valve spring and then tapered the sides of the poppet on a 5* angle to reduce the OD to that of the spring at the seat.... The support for the front end of the spring is made from a 1.5" long 8-32 SHCS with the head turned down a bit to fit inside the QB spring.... I made a tapered brass collar to slide over the screw to form the spring seat, and then drilled out a piece of 3/16" brass K&S hobby tubing to fit over the screw as a spacer to set the height.... The tank block will be drilled and tapped on center for the 8-32 screw....

It turns out that in a stock QB valve, the installed spring is compressed to 1/2" long, so as long as I have that distance between the spring seats I will have stock preload.... It works out in my QB79 that I need the front spring seat 1.035" from the tank block to acccomplish that.... Here is a view of the inside of the valve, showing what the flow is like....

(http://i378.photobucket.com/albums/oo221/rsterne/QB%20on%20HPA/IMG_3581_zps43eaa031.jpg) (http://s378.photobucket.com/user/rsterne/media/QB%20on%20HPA/IMG_3581_zps43eaa031.jpg.html)

If you compare that to a stock QB valve, you will see a huge difference.... The ID of a stock valve is 7/16", my valve is bored out to 1/2", which doubles the clearance around the poppet.... The aluminum ring I glued on is 1/4" long measured from the O-ring groove.... After the epoxy hardened, I machined out the front of the valve on a 30* angle until there was only about a 0.020" lip remaining.... That took the taper about half way to the seat.... I then changed the angle to 15* and knocked off the corner to smooth the flow even more....

The throat of a stock QB valve is 0.198" and the stem is 0.116".... I drilled the throat out to 7/32" (0.219") so that the throat area is larger than the rest of the porting I did in Stage 1.... I also blended the bottom of the exhaust port into the throat using a 5/32" ball grinder in a Dremel.... The distance from the valve seat to the tank block is just over 2", which gives a basic volume of 14.5 cc.... but by the time you subtract the volume of the poppet, spring, and forward spring mount, I ended up with a whisker over 12 cc.... While it's not as much as I'd like, it shouldn't cause too much loss in efficiency until the power goes over 25 FPE.... I'd frankly be very surprised to see that power level, even with my "Maxi-Valve" installed, when running at only 1200 psi....

Bob
Title: Re: QB79 Ninja - The $200 PCP
Post by: NinjaPaintballRay on July 18, 2013, 11:22:18 AM
Bob.  Amazing work.  This forum is very lucky to have someone with your knowledge helping people out.  Thanks for doing what you do.
Title: Re: QB79 Ninja - The $200 PCP
Post by: airpuffhunter on July 18, 2013, 11:46:54 AM
Hello Bob, a little bit off, but would it be possible to drill the barrel in the back, so you can make a pass trug a bolt to engage in the spacer behind the valve, replacing the one that comes stock, but holding the barrel in place.
so you don't have to remove the barrel from the receiver every time you want to disassemble the gun?
Title: Re: QB79 Ninja - The $200 PCP
Post by: rsterne on July 18, 2013, 03:11:03 PM
I drilled and tapped the tank block for the front spring mount and assembled the Stage 2 version of the gun this morning.... I was quite pleased with the results, as I have exceeded stock Disco performance with this version.... Here are the results from a 2000 psi to 1000 psi (tank pressure) string....

(http://i378.photobucket.com/albums/oo221/rsterne/QB%20on%20HPA/QBNinjaStage2_zps9b5f4c30.jpg) (http://s378.photobucket.com/user/rsterne/media/QB%20on%20HPA/QBNinjaStage2_zps9b5f4c30.jpg.html)

The first 22 shots averaged 864 fps (23.7 FPE), dropping below 860 fps only once the pressure dropped below 1200 psi which is the setpoint on my Ninja SHP Pro regulated tank.... That should give 50 shots on a full tank, which is pretty decent at that power level, even though the efficiency (to me) is a bit disappointing at only 0.74 FPE/CI....  It is quite possible that reducing the hammer spring preload would increase this efficiency somewhat.... The gun may well be operating on the "plateau" of the velocity curve, and reducing the hammer strike a bit may well not drop the velocity while increasing the shot count.... I'm pretty sure that dropping the velocity just a bit (20-30 fps) could add maybe 10-20 shots to the string, so that is something worth experimenting with at a future date.... If we could get the efficiency up to 1.0 FPE/CI at 22 FPE, 73 shots should be possible....

With the relatively small 12 cc plenum, which is only 1/2 cc per FPE at this power, the average pressure available per shot is less than 900 psi.... How is this possible?.... We start out with 12 cc (0.73 CI) of air at 1200 psi (83 bar), which is 60.6 CI of air a 1 bar.... Each shot is using 36 psi from the 13 CI tank, which is 32.3 CI of air at 1 bar.... Assuming the regulator response time is too short to add any useful quantity of air during the 1-2 milliseconds before the valve closes, at that moment we only have 60.6 - 32.3 = 28.3 CI of air at 1 bar left in the valve.... That means the pressure has dropped from 1200 psi to (28.3 / 60.6) x 1200 = 560 psi, so the average pressure during the shot is only 880 psi.... It shows how important plenum volume is in a regulated gun.... If we had double the plenum volume, the average pressure would be 1040 psi, much closer to the 1200 psi setpoint.... and the efficiency would be significantly higher.... On the other hand, this is pretty remarkable performance on a QB79 from only 1200 psi, thanks to the much increased volume of the "Maxi-Valve"....

About the only thing left to do is to test this gun running at 1500 psi, which is an easy level to achieve with the Ninja SHP Pro regulator and still be within the safety levels provided by the 1.8 K burst disc.... How to change the regulator to that output is in the separate thread on the Regulator referenced in the first post in this thread.... As time permits, I will be doing that and reporting the results....

Bob
Title: Re: QB79 Ninja - The $200 PCP
Post by: rsterne on July 18, 2013, 09:42:51 PM
I swapped out the tank for the other one that I had set up for 1500 psi.... I wasn't quite sure what to expect, as normally that is too much pressure for stock hammer spring preload on a QB78.... As it turns out, with the smaller plenum of the QB79, the pressure drop during the shot compensates for the extra pressure at the beginning of the shot.... allowing the stock hammer spring to work OK.... Here are the results of the Stage 2 tune running at 1500 psi....

(http://i378.photobucket.com/albums/oo221/rsterne/QB%20on%20HPA/QBNinja1500Stage2_zps6fe7e17e.jpg) (http://s378.photobucket.com/user/rsterne/media/QB%20on%20HPA/QBNinja1500Stage2_zps6fe7e17e.jpg.html)

As before, the starting pressure was 2000 psi, and the ending pressure was 1000.... I got 16 shots averaging 918 fps (26.8 FPE) down to 1400 psi before the velocity started to drop below 900 fps.... The fact that the drop in velocity starts 100 psi below the regulator setpoint indicates that this tune is operating very close to the "knee" of the curve where I like to tune my regulated guns.... The efficiency was higher than at 1200 psi, working out to 0.80 FPE/CI, and I should be able to get 42 shots @ 27 FPE on a 3000 psi fill.... That a pretty serious hunting platform....

When I did the calculations for the pressure during the shot for the 12 cc Plenum, I get 836 psi at the end of the shot, and an average pressure of 1168 psi during the shot.... That gives a pretty good indication of why the stock hammer spring preload is working so well with this setup.... It also confirms that running 1200 psi on the Stage 2 tune is running less efficiently than it could because the hammer energy is too much for the 880 psi average pressure.... I now have no doubt that reducing the preload a bit on that tune will increase the shot count with little or no velocity loss.... I'm going to have to give some thought to what is the easiest way to accomplish that, as fitting an RVA to a QB isn't the easiest thing to do, and I want it adjustable, I don't want to just clip the hammer spring....

Bob
Title: Re: QB79 Ninja - The $200 PCP
Post by: rsterne on July 18, 2013, 11:23:58 PM
Just out of curiosity I flung a few 18.1 gr. JSB Heavies through the Chrony.... They did 855 fps (29.4 FPE).... That's 3 FPE better than the best I ever did with a QB79 at 1500 psi with those pellets previously.... so the new "Maxi-Valve" certainly works great.... Also, so far, it doesn't seem to leak, despite not having the O-ring "squeezed" between the valve halves.... I would say the "Maxi-Valve" idea is a complete success in the QB79....

Bob
Title: Re: QB79 Ninja - The $200 PCP
Post by: joel w on July 18, 2013, 11:58:48 PM
Thanks Bob, I think you have just added to my addiction by giving me my next project.   ;D

Brilliant!
Title: Re: QB79 Ninja - The $200 PCP
Post by: Froggy. on July 19, 2013, 04:29:48 AM
Bob, change the cocking action to a pull rather than push...easy to add a hammer spring adjuster like the 2240 crosman.
Title: Re: QB79 Ninja - The $200 PCP
Post by: rsterne on July 19, 2013, 02:45:31 PM
I agree, Froggy.... The problem is, that the spring then holds the bolt forward, eliminating virtually all of the loading room for the pellet.... You have to either hold the bolt back during loading, or make another notch at the back to do that, like this....

(http://i378.photobucket.com/albums/oo221/rsterne/QB%20on%20HPA/IMG_2133.jpg) (http://s378.photobucket.com/user/rsterne/media/QB%20on%20HPA/IMG_2133.jpg.html)

I may well do that if I can't come up with a better solution.... without resorting to the complicated RVAs others have built for QB's that are still "cock on close"....

Bob
Title: Re: QB79 Ninja - The $200 PCP
Post by: Ribbonstone on July 19, 2013, 06:29:28 PM
Not really a solution, but it does make it marginally easier to tune a QB.  I leave everything off I possibly can between spring changes.

No safety, no stock, no barrel band, not scope.  Just the bare metal work, set in bags, shooting over the chronograph bare-barreled.

Is one of the reasons I use an on/off between the tank and the gas block.  PROBABALY safe to remove one of the retaining screws (the front action screw) in order to swap springs, but I’d much rather turn the on/off to “off” and fire off the pressure in the tube firs (but keep the pressure in the bottle while I do it).

Once I get where I wanted to go,  put it all together again and then worry about accuracy.

Which might be my 2nd point: I usually have a definitive goal.  Either “X” amount of energy or “x” amount of shots per fill (or both).  If I was testing the limits, then it would be a never ending process and I’d just have to figure out an acceptable way to adjust mainspring tension externally.  I'm personally glad you push the limits (but it's a greedy though as well, you do it so i don't have to).

Then again, I do shoot a Raider, so the 2nd bolt notch isn’t too odd an idea for me to deal with.
Title: Re: QB79 Ninja - The $200 PCP
Post by: rsterne on July 19, 2013, 06:37:37 PM
I drew out a couple of different methods, none of which I liked, so I decided to go to the above system which works really well.... The end block is drilled off-center for a 2" long 10-24 SS screw as in the photo.... The set screw in the side of the block pushes a piece of Delrin rod against the side of the screw to act as a brake so it won't self-adjust.... All I have left to do is mill the second down-slot at the back of the bolt travel, remove the rear cocking pin to convert to "cock on open", and I'll be ready to go.... I use an RVA so much when I'm tuning I feel lost without it.... I absoultely HATE having to swap out springs (and clip them) all the time....

Bob
Title: Re: QB79 Ninja - The $200 PCP
Post by: supertech77 on July 19, 2013, 07:37:41 PM
just as you said bob, it works great on the 850 hammerli, with the long valve previously installed to go 9oz co2, as i have done all the other mods listed on the 850 site, i filled to 2500psi, and i have not set up a crony on it yet but its banging threw a 1inch phone book where it use to only go in 1/2 way, thanks for your idea,i did have to remove 1 inch of the stock to make it fit with the gauge and fill nipple, but it works great;;;; happy,happy,happy  ;D now the 850 is hpa,
Title: Re: QB79 Ninja - The $200 PCP
Post by: rsterne on July 20, 2013, 02:52:05 PM
Well, sometimes you pay for not keeping good notes.... I made an offset RVA as in the photo above, removed the rear cocking pin to convert to "cock on open", and machined a new downwards slot to hold the bolt back while loading the pellet.... The only problem was, that the version I previously did that on had a shortened hammer and guide pin on the cocking block to allow the bolt to be drawn back further without it bottoming out.... When I adjusted the RVA so that I could push the bolt down into the rear slot, the hammer spring didn't have near enough preload on it.... Rather than modify the hammer and guide pin, I made a spacer to slide over the guide pin on the cocking block to increase the hammer spring tension.... The spacer was 0.35" OD, 0.22" ID, and 0.30" long, so it adds that much preload, and allows the gun to function properly.... I then proceeded to test the velocity at various preloads, with the following results....

(http://i378.photobucket.com/albums/oo221/rsterne/QB%20on%20HPA/QBNinjaEfficiency1500_zps9a15ffd6.jpg) (http://s378.photobucket.com/user/rsterne/media/QB%20on%20HPA/QBNinjaEfficiency1500_zps9a15ffd6.jpg.html)

You can see the typical plateau in velocity you get on a regulated gun when the hammer strike is more than required.... The velocity doesn't increase, the gun just uses more air.... One slightly unusual thing on this graph, is that the efficiency falls off on the right side as well.... For some reason, the power drops off quicker than the air usage when the gun is detuned below 800 fps in this Stage 2 configuration.... My choice with this setup, at 1500 psi, would be to tune the gun for just over 900 fps (26 FPE).... I would expect about 50-60 shots at that power level.... Pushing for more power than that with a QB79, even with the "Maxi-Valve" simply wastes air....

Bob
Title: Re: QB79 Ninja - The $200 PCP
Post by: rsterne on July 21, 2013, 02:28:05 AM
Here are the results of a full string starting at 3000 psi using the Stage 2 "Maxi-Valve" setup running at a regulator pressure of 1500 psi.... I set the RVA to 2.5 turns out, which set the velocity just where the "knee" of the curve starts, with the 14.3 gr. Crosman CPHPs....

(http://i378.photobucket.com/albums/oo221/rsterne/QB%20on%20HPA/QBNinjaString1500_zps434961a3.jpg) (http://s378.photobucket.com/user/rsterne/media/QB%20on%20HPA/QBNinjaString1500_zps434961a3.jpg.html)

The average velocity was 908 fps (26.2 FPE) with a high of 914 and a low of 902 for an ES of 12 fps (1.3%) over the first 58 shots.... Shot 62 was just outside a 2% ES and wasn't counted, and the pressure at that point was 1300 psi.... As is typical when you tune a regulated gun to the "knee" of the velocity curve, you can shoot a couple of hundred psi below the setpoint before the velocity takes a dive.... The efficiency worked out to 1.07 FPE/CI, which for this power level in a QB79 is pretty astounding....

I'm extremely pleased with the results of this testing.... I think it would be very difficult to get more power than this from a QB79 without major changes to allow running a burst disc higher than the 1.8K which is required for safety the way the gun is produced.... While more power could be produced from a QB78 because of the larger tube, when you consider the simplicity of just screwing a tank onto a QB79 to convert it to a PCP it's a pretty impressive combination.... I will be re-fitting the 1200 psi standard SHP Pro regulator for final testing shortly....

EDIT: I should mention that using heavier pellets would increase the FPE.... 18 gr. would give about 29 FPE, 25 gr. about 32 FPE, and 32 gr. about 35 FPE....

Bob
Title: Re: QB79 Ninja - The $200 PCP
Post by: Raizer on July 21, 2013, 02:32:06 AM
That gun is coming along in leaps and bounds mate!
Title: Re: QB79 Ninja - The $200 PCP
Post by: rsterne on July 21, 2013, 10:28:32 PM
Today I refitted the stock Ninja SHP Pro regulated tank to the Stage 2 QB79.... I then shot 10-shot strings to check the velocity and air pressure drop for different hammer spring preloads so that I could calculate the efficiency.... Here are the results....

(http://i378.photobucket.com/albums/oo221/rsterne/QB%20on%20HPA/QBNinjaEfficiency1200_zpscdcebe24.jpg) (http://s378.photobucket.com/user/rsterne/media/QB%20on%20HPA/QBNinjaEfficiency1200_zpscdcebe24.jpg.html)

As I suspected during the initial testing of this version, the stock hammer strike was too much, wasting a significant amount of air.... The original tune suggested about 50 shots on a fill, but if the efficiency could be bumped up to 1.0 FPE/CI I predicted 73 shots.... Now I'm pretty confident that can be met or exceeded, since at 4 turns out I was seeing an efficiency of about 1.15 FPE/CI.... Now when using only 10 shots, and a gauge with 100 psi increments, it's easy to have some errors creep in.... but that 10 shot string only used 220 psi, or 22 psi per shot.... while returning 845 fps (22.7 FPE).... I'm looking forward to running a full string starting from 3000 psi as soon as I have my SCUBA tank topped up....

Bob
Title: Re: QB79 Ninja - The $200 PCP
Post by: rsterne on July 22, 2013, 02:15:23 AM
Here is the shot string with the hammer spring preload at 4 turns out.... This is for the Stage 2 tune with the "Maxi-Valve", using a stock Ninja SHP Pro regulated 13 CI tank filled to 3000 psi.... I was using 14.3 gr Crosman CPHP pellets....

(http://i378.photobucket.com/albums/oo221/rsterne/QB%20on%20HPA/QBNinjaString1200_zpscd2bcd5a.jpg) (http://s378.photobucket.com/user/rsterne/media/QB%20on%20HPA/QBNinjaString1200_zpscd2bcd5a.jpg.html)

The average velocity was 847 fps (22.8 FPE), and over the first 80 shots the highest velocity was 854 fps and the lowest 841 fps, for an ES of 13 fps (1.5%).... Only the last shot dropped below 840, and it still fell within 2% of the highest, and the pressure at that point was 1070 psi.... That works out to an efficiency of 1.07 FPE/CI, interestingly the same figure as I got yesterday shooting at 1500 psi....

Getting 80 shots in a flat string at slightly better than stock Disco power is nothing short of amazing.... I think this is the way I'm going to leave this rifle.... It makes one heck of an entry level PCP.... Here is a summary of the three tunes using the Ninja SHP Pro Regulated 13 CI tank, shooting 14.3 gr. Crosman CPHPs....

Stock QB79:  135 shots at 609 fps (11.8 FPE)
Stage 1 Tune (top end work only): 105 shots at 738 fps (17.3 FPE)
Stage 2 Tune (Maxi-Valve): 80 shots at 847 fps (22.8 FPE)


Note that in order to get the extended shot count in Stage 2, I had to REDUCE the hammer spring preload from stock.... I have a feeling that the shot count in a Stage 1 tuned gun (and possibly even a Stock gun) could be improved a bit by the same method.... Although I chose to use and RVA and convert the gun to "cock on open", simply clipping a bit off the hammer spring would have the same result....

Although my Maxi-Valve, IMO, is getting just about all the performance possible from a QB79 at this pressure.... I would like to point out that there are commercially available valves from several sources that have the piercing pin and filters removed and the sides of the valve opened up to increased flow into the valve.... I'm guessing that they would be in the 800+ fps range when used with the porting done in Stage 1, when operating with this tank and reg.... I would highly recommend the Ninja SHP Pro 13CI Tank and Regulator combination as an inexpensive and yet excellent way to convert a QB79 to HPA.... All the same mods that are used in the CO2 versions also work to enhance the performance of the PCP version, which is a big bonus....

Bob
Title: Re: QB79 Ninja - The $200 PCP
Post by: supertech77 on July 22, 2013, 09:05:18 AM
Thank you bob, for another excellent post;   ;D
Title: Re: QB79 Ninja - The $200 PCP
Post by: airpuffhunter on July 22, 2013, 09:41:30 AM
your work on qb is always good. excellent post thank you
Title: Re: QB79 Ninja - The $200 PCP
Post by: rsterne on July 25, 2013, 12:15:52 AM
I'm pretty ticked right now.... The gun fell off the bench last night (I have no idea how, it's like it just rolled over the edge).... When it landed on the floor it got two dents and a crease in the comb of the stock.... no marks on the metal I have found, and it still shoots fine.... I'm pretty bummed, thinking of just getting rid of it.... either that or putting on a Richards walnut thumbhole stock I have sitting here....

Bob
Title: Re: QB79 Ninja - The $200 PCP
Post by: NinjaPaintballRay on July 25, 2013, 12:34:37 PM
I'm pretty ticked right now.... The gun fell off the bench last night (I have no idea how, it's like it just rolled over the edge).... When it landed on the floor it got two dents and a crease in the comb of the stock.... no marks on the metal I have found, and it still shoots fine.... I'm pretty bummed, thinking of just getting rid of it.... either that or putting on a Richards walnut thumbhole stock I have sitting here....

Bob

Have you checked your burst disks yet Bob?  I wonder if one blew and the pressure could have "pushed" the gunoff the bench. 
Title: Re: QB79 Ninja - The $200 PCP
Post by: rsterne on July 25, 2013, 01:20:28 PM
Nope, not that.... Gremlins, I guess....

Bob
Title: Re: QB79 Ninja - The $200 PCP
Post by: Gesshoku on July 25, 2013, 03:56:21 PM
Love reading these breakdowns. Especially on my favorite QB! And I'd be happy to take that off your hands, I'll gladly pretend the dings aren't there. :P
Title: Re: QB79 Ninja - The $200 PCP
Post by: Ribbonstone on July 25, 2013, 06:41:05 PM
Guess about 1/2 of them have succumbed to gravity over the years.  My explanation is this: lemmings.  Got too many guns for too little sapce, and once the first one goes off the cliff, others follow. Onto cement, hard pan, gumbo mud, salt water,  rock slides, train tracks, etc. 

But I don't mind the "honest" wear from hunting, will often look at those repaired dents/cracks and think of the hunt I was on when it happened. The ones where the gun just hit the ground for no good reason I can tell do tend to remind me of (1) the fallibility of their owner and (2) Mruphy's Law.

Once dropped a hunting rifle (PB) into 8 feet of dark bayou water (OK..was a service canal to an oil rig, but same thing). Winter.  Had to get naked (to have somtehing warm to wear after the event) and bare footed.  Too deep to just walk around, so was bobboing up and down like a cork, feeling the bottom with my feet.  Cold, but unless I stepped on a gator he wasn't going to bother me and the snakes were all in.

Round the bend comes a "party barge" with an extended family (or it might have been tourist). One the way in, they got to see the naked guy bobbing up and down in the bayou.  On the way out, they got to see the blue/shivering naked man huddle around a fire trying to dry off himself and the rifle.

Kind of a flat lander (living in South Lousiana).  Hunting Va (around the Cumberland Gap, so in HillBilly hand) managed to grab a tree before going off a ledge.  Rifle did't have that choice, and off she goes, free fall for about 20-22 feet onto a rock fall jumble.  Turned my 12X Unertel (one of the old long target scopes)  into a shallow "V". Ruined that hunt. But I'll be darned if Unerle didn't fix that scope (guessing this was about 1972), and if they charged me at all, it was a small amount.
Title: Re: QB79 Ninja - The $200 PCP
Post by: NinjaPaintballRay on July 26, 2013, 11:44:11 AM
Once dropped a hunting rifle (PB) into 8 feet of dark bayou water (OK..was a service canal to an oil rig, but same thing). Winter.  Had to get naked (to have somtehing warm to wear after the event) and bare footed.  Too deep to just walk around, so was bobboing up and down like a cork, feeling the bottom with my feet.  Cold, but unless I stepped on a gator he wasn't going to bother me and the snakes were all in.

Round the bend comes a "party barge" with an extended family (or it might have been tourist). One the way in, they got to see the naked guy bobbing up and down in the bayou.  On the way out, they got to see the blue/shivering naked man huddle around a fire trying to dry off himself and the rifle.

Great story haha!  Thanks for the good laugh this morning :)
Title: Re: QB79 Ninja - The $200 PCP
Post by: sixshootertexan on July 26, 2013, 09:40:43 PM
Stock QB79:  135 shots at 609 fps (11.8 FPE)

What is the shot count and FPS on CO2?
This is a .22 cal right?
Title: Re: QB79 Ninja - The $200 PCP
Post by: evandj on July 26, 2013, 11:04:22 PM
Wow, great work and sorry about the gun mishap.
Title: Re: QB79 Ninja - The $200 PCP
Post by: rsterne on July 27, 2013, 12:00:05 AM
CO2 = no idea, but stock velocity is under 500 fps in .22 cal.... The Stage 1 tune is about 600 fps on CO2, and ~738 on HPA....

The gun is being fitted with my Richards thumbhole stock, and it's coming out quite well.... It's also getting a scope and air stripper....

Bob
Title: Re: QB79 Ninja - The $200 PCP
Post by: Pursang on July 31, 2013, 10:43:27 AM
Archer now offer a repeater 78/79 that uses Marauder magazines for $300, or an upgrade kit for $160.
Title: Re: QB79 Ninja - The $200 PCP
Post by: rsterne on July 31, 2013, 12:55:24 PM
So that would give you a PCP repeater for well under the $400 price point....

BTW, my Richard's Wildcat QB78 Thumbhole stock is inletted for the tank and I'm in the process of finishing it.... It's a Select Black Walnut with Ebony grip cap and is turning out quite spectacular....

Bob
Title: Re: QB79 Ninja - The $200 PCP
Post by: Edtampa on July 31, 2013, 09:33:38 PM
Bob, is this also possible with a QB78 deluxe? I have one that has been power tuned by MM shooting 650-725 FPS depending on the pellet weight. What gains would I expect from going HPA?
Thanks

Ed
Title: Re: QB79 Ninja - The $200 PCP
Post by: rsterne on July 31, 2013, 11:31:40 PM
You can convert a QB78D by shortening the tube a bit to get rid of the threads (you need to get back to full wall thickness for the tank block) and then drill the tube to mount the tank block.... I wouldn't go as short as a QB79 tube because of the lack of volume between the regulator and valve.... I did one with a 3" longer tube than a QB79, and I was able to tune it for well over 30 FPE at 1500 psi.... One thing to consider, however, is that ideally you should inlet the QB78 stock to fit the tank block, and install the screw that mount the stock to the block for safety.... If you don't do that, then you should look at beefing up the tank block mounting screws, both as to material and location.... On possibility it to use the JDS tank block as the screws are further from the end, and then use high tensile screws.... Safety First !!!

As to velocity, running 1100 psi HPA you should get at least 100 fps more than what you do with CO2 in most situations.... However, more is available with HPA if you do the appropriate mods to take advantage of it....

Bob
Title: Re: QB79 Ninja - The $200 PCP
Post by: Edtampa on August 01, 2013, 12:26:02 AM
Bob,

Thanks for the reply. trying to decide if I should spend additional funds on the QB or apply it towards a DISCO and have a better platform for the future.

Ed
Title: Re: QB79 Ninja - The $200 PCP
Post by: rsterne on August 01, 2013, 12:51:31 AM
It depends entirely on what you want.... IMO the Disco can be modded to higher FPE levels at it's 2000 psi fill than the QB which is limited to having a 1.8K burst disc on the regulator, which means a maximum usuable pressure of about 1500 psi.... Now if you put a regulated tank on the Disco and don't beef up the valve mounting screws, you will face a similar limitation of course.... Both guns can with significant modifications (in the QB it takes a new tube) be made to operate safely at higher pressures, but that is beyond what most shooters can/will do....

Bob
Title: Re: QB79 Ninja - The $200 PCP
Post by: Ribbonstone on August 01, 2013, 12:25:29 PM


IF you are an experimenter with at least some access to a few tools, the QB is an experimenter's dream. Can run one from 12gr., from bulk fill, from co2 tanks, from HPA tanks, and (with a tube switch) as a PCP. They've kept me entertained for years and if I'm honest, modded QB's could do everything I want or need an airgun to do.

Seems to be a lack of PCP tubes being made for sale, although individuals have made them for theirown use; that option is kind of closed for the hobbiest time being. 


IF looking for power, would convert a 78 tube to HPA.  If less than mega-power, then start with a standard 79.

On the other hand, when I pick up a Discovery, am reminded of just how lite and simple those guns are. Long, but light, they carry well in the field. Won't get the shot count of a regulated HPA, but you can open the box and get to shooting.  Hunting, I don't miss the shot count (I'd be lucky to get 8-10 good shots on squirrels in an afternoon).

Title: Re: QB79 Ninja - The $200 PCP
Post by: rsterne on August 01, 2013, 12:43:30 PM
Quote
IF looking for power, would convert a 78 tube to HPA.  If less than mega-power, then start with a standard 79.
I agree 100%.... Even with my "Maxi-Valve" there simply isn't enough volume between the regulator and the valve for big power in a QB79, and the need to run a 1.8K burst disc for safety seals the deal.... 30 FPE is about the maximum....

Here is a previous thread in which I dealt with the effect of the difference in volume in detail.... http://www.gatewaytoairguns.org/GTA/index.php?topic=21681 (http://www.gatewaytoairguns.org/GTA/index.php?topic=21681)

I agree about not needing a ton of shots when hunting (other than maybe gophers, where I might get 100 shots in a day).... My Grouse gun is a PCP based on a 2260 tube.... It is tuned for 16 shots at 20 FPE.... I have shot my limit several times, and missed a few along the way, and I've never had to refill the gun in the field during a days hunting.... This QB79, with 80 shots at 23 FPE, however, would be as good a gopher gun as you could get.... *grin*....

Bob
Title: Re: QB79 Ninja - The $200 PCP
Post by: rsterne on August 01, 2013, 11:50:19 PM
Sometimes leaks can be a good thing.... I've had a slow leak in this gun virtually since new.... It lost about 600 psi the first day, then 3-400, then a trickle.... I tested everything with soapy water and couldn't find anything, which pretty much meant it was the valve.... I pulled the breech, and found a very small leak coming out the exhaust port, so it was the poppet that wasn't sealing on the seat.... I pulled the gun all apart, and on inspecting the seat with a loupe I saw a very small nick on the sealing surface, and a corresponding mark on the soft seal insert on the poppet.... The brass seat was easy to polish, but rather than take a chance on the seal in the poppet I decided to replace the poppet head with a Delrin one which is more suitable for HPA use.... I drove the stem out of the old poppet and reused the stem, and made a new poppet head from a piece of 3/8" Delrin.... Since I didn't have to worry about the OD of the brass poppet, I was able to turn the entire head down to 0.32", which is the diameter of the valve spring, and 0.050" smaller than the original.... I lapped the new poppet against the repaired seat, and reassembled the gun....

The first test shots, with the RVA set at 4 turns out as before, were a bit of a shocker.... Instead of getting 847 fps (22.8 FPE), the velocity was in the high 880s with the occasional 890+ (25.0 FPE).... Obviously the new Delrin poppet was a big improvement.... Since the throat and seat is still the same size, I figure the increase must be from the decrease in head diameter and the corresponding easing of the flow around it.... There was another big change, and this one I expected.... I was able to reduce the hammer spring preload another 2 turns to get back to the "knee" of the velocity curve.... This is because the harder seal material compresses less, and that reduces the amount of hammer energy required to "unstick" the valve from the seat.... It sure is nice to see theory backed up by results....

Bob
Title: Re: QB79 Ninja - The $200 PCP
Post by: Millipede on August 02, 2013, 02:58:19 AM
i was wondering when you would put a delrin stem in there..  i just ordered a couple from mountainair for my own qb79 since i noticed how deeply indented the original stem seal was the last time i had it apart
Title: Re: QB79 Ninja - The $200 PCP
Post by: Ribbonstone on August 02, 2013, 08:03:58 AM
HAve swapped to Delrin stems in a couple of conversions, will probably end up with them in all of them sooner or later.  Do use the original at first, and when that blows, will switch to a Delrin stem.  Some of the rifles are still going strong on the issue valve stem, even after a couple of years of use but all of mine run at 800-850psi which probably doesn't stress them much.
Title: Re: QB79 Ninja - The $200 PCP
Post by: neric on August 02, 2013, 08:18:42 AM
Very nice post.  Really enjoyed the read.  I may have to dive into this project myself.
Title: Re: QB79 Ninja - The $200 PCP
Post by: rsterne on August 02, 2013, 01:42:37 PM
I've used factory valve poppets up to 1600 psi with good success.... The last time I had a problem I disassembled the brass poppet and just replaced the seal material with a Delrin washer I made.... and promptly LOST a few fps.... I have NO explanation as to why, the results I got this time were much more satisfying.... I certainly wouldn't have bothered replacing the stock seal for use at 1100-1200 psi, as CO2 sees those pressures any time it gets hot outside.... However, slimming up the poppet seems to be advantageous, so I'm glad I did.... I doubt if swapping out the poppet for a Delrin one (even a slimmed one) would have changed the performance in a Stock or Stage 1 gun.... other than it might actually waste more air if you don't back off the hammer spring preload to compensate for the additional (and unnecessary) lift with the harder material....

If you are modding a QB78, with the larger plenum volume, and running over 1200 psi, I can see the Delrin poppet adding to the performance when using a stock hammer spring preload.... This is because it is easier to knock off the seat, leaving more hammer energy to produce lift and dwell against the higher average pressure in the larger tube.... What I'm saying is that with a Delrin poppet the velocity with a stock hammer strike would likely max. out at a higher pressure....

Bob
Title: Re: QB79 Ninja - The $200 PCP
Post by: ericw on August 02, 2013, 02:43:33 PM
I figure the increase must be from the decrease in head diameter and the corresponding easing of the flow around it.... There was another big change, and this one I expected.... I was able to reduce the hammer spring preload another 2 turns to get back to the "knee" of the velocity curve.... This is because the harder seal material compresses less, and that reduces the amount of hammer energy required to "unstick" the valve from the seat.... It sure is nice to see theory backed up by results....

Bob

I find this experiment to be real interesting Bob.  Have you ever considered trying to make the poppet head more aerodynamic to improve air flow? If making it a bit smaller has this much effect it makes me wonder.   Also, it is interesting to note that with near zero compression of the poppet, the energy required to open it also goes to zero (E=Force * distance).   
Title: Re: QB79 Ninja - The $200 PCP
Post by: rsterne on August 02, 2013, 04:20:29 PM
The valve spring is 0.32" diameter, so I made the poppet the same diameter.... You can't go a lot smaller on the seat end, although you could slim it a few more thou.... I don't think using a "coke bottle" shape like they do for the fuselage in supersonic aircraft is worth it (and might be worse).... besides that is to allow for the cross sectional area of the wings (the "area rule")....

While you may think the compression on the poppet is "near zero", let me assure you it isn't zero.... I measured it on a Disco with a Delrin poppet and got about 0.007" of compression at 1200 psi.... The seats are about the same diameter, so at 1200 psi, the force is about 79 lbs, plus 7 for the spring for a total of 86 lbs.... To calculate FPE, you use half the force (the average, it's zero when compressed), so you get:

FPE = 86/2 x 0.007/12 = 0.025 FPE of hammer energy to "unstick" the valve.... If you triple the compression of the seal material (to 0.021", maybe a good guess) you would get 0.075 FPE of hammer energy sucked up before the valve even cracks with a stock (soft) seal....

I haven't calculated the hammer energy in a QB, but in a Disco, the Delrin poppet not worthy up about 18% of the available hammer energy (0.29 FPE) just to unstick at 2000 psi....

Bob
Title: Re: QB79 Ninja - The $200 PCP
Post by: rsterne on August 03, 2013, 02:50:30 PM
Here is the results of preliminary pellet testing indoors at 20 feet....

(http://i378.photobucket.com/albums/oo221/rsterne/QB%20on%20HPA/QB79HPAPellets_zps09d136f6.jpg) (http://s378.photobucket.com/user/rsterne/media/QB%20on%20HPA/QB79HPAPellets_zps09d136f6.jpg.html)

I shot 5 shot groups from the bench, and then sorted the results by using two washers of 3/8" and 1/2" diameter.... If the 3/8" washer completely covered the group, it is coded green above.... If the 1/2" washer would NOT cover the group, it is coded red.... All others (3/8" to 1/2") are left unmarked.... The best group was the 15.9 gr. JSB Exact Jumbo, which was just a ragged hole, closely followed by the other JSB Exact Series pellets....

The Ballistics Coefficients listed are taken from testing over 25 yards with another gun that shot about 1 FPE more muzzle energy, so they will be very close in this gun.... Pellets shown in blue will be tested at longer range....

Bob
Title: Re: QB79 Ninja - The $200 PCP
Post by: rsterne on August 04, 2013, 02:23:09 AM
Today I added a Hatsan Air Stripper to the barrel and did a few tests with the JSB Exact 15.9 gr. pellets which produced the best groups yesterday.... I had never tested a stripper before, so I set the gap between the stripper cone and the barrel at maximum (about 2 calibers gap from the muzzle) and then moved it in about 1/2 cal. for each group.... I shot 5 shot groups through the Chrony with the target still at 20 feet, not knowing what to expect....

Without the stripper, the velocity was 849 fps, and with the gap at maximum it seemed to be a couple of fps less.... Each time I moved the stripper closer to the muzzle it picked up a couple of fps, and by the time the gap was down to just over 1/16", the velocity was 855 fps.... I figure that when the gap is small, the stripper is focusing some of the muzzle blast behind the pellet and effectively lengthening the barrel a fraction, although not very efficiently.... The group size did, in fact, seem to vary as I adjusted the gap, although at this short range realistically the changes were very small.... I expect it would be easier to see results at longer ranges.... Since the smallest group seemed to be with a gap of just under 1/4", I decided to adjust the gap to exactly the same size as the head of the pellet (just because) so I clamped a pellet in some forceps and them used the head like a feeler gauge and adjusted the stripper cone so that the pellet just touched it and the muzzle.... Here is the 5-shot group I shot at that setting....

(http://i378.photobucket.com/albums/oo221/rsterne/QB%20on%20HPA/QB79HPA002_zpsc3a09512.jpg) (http://s378.photobucket.com/user/rsterne/media/QB%20on%20HPA/QB79HPA002_zpsc3a09512.jpg.html)

That is a .22 cal JSB Exact sitting in the hole.... The target won't meet the Feinwerkbau test where a pellet will hang in the hole with the target vertical, but it won't fall through either.... I figure the group is 0.03 - 0.04" C-T-C, or about 0.25"-0.26" OD.... In any case, I'm pretty pleased with it, and indeed the stripper seems to help....

Bob
Title: Re: QB79 Ninja - The $200 PCP
Post by: supertech77 on August 04, 2013, 08:47:16 PM
nice shooting,  :o  i would say its dialed in at 20feet very nicely..  ;D
Title: Re: QB79 Ninja - The $200 PCP
Post by: rsterne on August 05, 2013, 02:33:55 AM
I tested the efficiency at various hammer spring preloads today, using the 15.9 gr. JSB Exact Jumbo pellets which are very accurate in this gun.... The new slimmer Delrin valve has picked up about 2 FPE, so it shoots the 15.9 gr. pellets at nearly the same velocity as it did the 14.3 gr.... I had to back the preload out several turns relative to the stock poppet because the harder Delrin is much easier to knock open than the soft seal on the stock valve.... Here are the results....

(http://i378.photobucket.com/albums/oo221/rsterne/QB%20on%20HPA/QB79NinjaDelrin1200_zpsb290e1ce.jpg) (http://s378.photobucket.com/user/rsterne/media/QB%20on%20HPA/QB79NinjaDelrin1200_zpsb290e1ce.jpg.html)

The efficiency seems slightly higher than before, and the plateau starts at 6 turns out instead of 3.5 turns.... Based on the results, I tried a short string at 6.5 turns out, and the velocity was only about 10 fps below the plateau and the efficiency was about 1.10 FPE/CI.... I think that's pretty good for a QB79 shooting at 25 FPE, and it's likely where I will end up tuning it.... That should give me over 70 shots per fill....

Bob
Title: Re: QB79 Ninja - The $200 PCP
Post by: Millipede on August 05, 2013, 03:09:13 AM
Hey bob, for those people who want to emulate this but can't make a hammer spring adjuster; how much of the spring should we cut off to give us the same power and shot count as yours?

Also can't you adjust the output of a regular ninja tank just by adding a shim or two to the regulator?
Title: Re: QB79 Ninja - The $200 PCP
Post by: Millipede on August 05, 2013, 03:12:37 AM
Btw, thank you for sharing all of your experience with us, it is very helpful and also fun to read about :-)
Title: Re: QB79 Ninja - The $200 PCP
Post by: rsterne on August 05, 2013, 01:01:57 PM
Yes to both questions.... How much to cut off the hammer spring is the question, but the solution is relatively easy, cut off a 1/4 turn at a time until the velocity starts to drop.... Since the spring rides on a guide, I don't even think you would have to worry about closing up the last coil, just put the cut end on the spring guide on the cocking block.... You can increase the pressure of the Ninja regulator by adding some thin shims, or by replacing the three shims inside with one more Belleville.... I covered that in this thread.... http://www.gatewaytoairguns.org/GTA/index.php?topic=49648.0 (http://www.gatewaytoairguns.org/GTA/index.php?topic=49648.0)

I would NOT go beyond 1500 psi on a QB79, and then only if you still have the 1.8K burst disc fitted.... The closer you go to 1800 psi, the more likely you are to pop the disc, I can tell you that for sure they fail occassionally at 1600.... In addition, any time you have gas in a QB79 (HPA or CO2) you should have the action bolted into the stock so that the two front stock screws are screwed into the tank block for additional safety....

Bob
Title: Re: QB79 Ninja - The $200 PCP
Post by: rsterne on August 05, 2013, 07:18:58 PM
I finished and installed the stock today....

(http://i378.photobucket.com/albums/oo221/rsterne/QB%20on%20HPA/IMG_3592_zps58f80da4.jpg) (http://s378.photobucket.com/user/rsterne/media/QB%20on%20HPA/IMG_3592_zps58f80da4.jpg.html)

It's a Richard's Microfit Wildcat Thumbhome in Select Grade Black Walnut with Ebony Grip Cap.... beautiful figuring in the grain....

(http://i378.photobucket.com/albums/oo221/rsterne/QB%20on%20HPA/IMG_3595_zps685d0609.jpg) (http://s378.photobucket.com/user/rsterne/media/QB%20on%20HPA/IMG_3595_zps685d0609.jpg.html)

I had to shorten the forearm and inlet it for the tank block and regulator.... The finish is 7 coats of Watco Danish Oil, each coat wet sanded, ending with a white Scothbrite pad of 1200 grit equivalent and then a coat of Dark Minwax.... The scope is a Leapers 3-9 x 32 AO with Sunshade.... The gun weighs 8 lb. 7 oz. as shown.... The Air Stripper is from a Hatsan PCP, I threaded the barrel 1/2"-20 NF to accept it....

It's no longer a $200 PCP, however....

Bob
Title: Re: QB79 Ninja - The $200 PCP
Post by: jessered on August 05, 2013, 07:21:40 PM
IT'S SO PURTY!!!!!
Title: Re: QB79 Ninja - The $200 PCP
Post by: rsterne on August 06, 2013, 03:21:00 AM
I made one more slight change today before the final testing.... The off center RVA screw was canting the cocking block slightly, and I noticed a slight scuff mark on the spring spacer.... I made a longer, one piece cocking block, with an integral spring guide and spring spacer.... The new cocking block is 1.25" long, of which 0.25" is a spring spacer that is 0.34" diameter, the other inch being full diameter to eliminate it canting in the tube.... That allowed me to shorten the RVA screw and just tidy things up a bit.... It shouldn't have changed the performance at all, but in fact I picked up about 10 fps, and gained a bit of efficiency as well.... The Preload numbers have changed, as I can't put quite as much preload on the spring at maximum with the shorter spacer.... Here is a new graph of Velocity and Efficiency vs. Preload using the JSB 15.9 gr. Exact Jumbos pellets....

(http://i378.photobucket.com/albums/oo221/rsterne/QB%20on%20HPA/QB79NinjaDelrin1200_zps999456be.jpg) (http://s378.photobucket.com/user/rsterne/media/QB%20on%20HPA/QB79NinjaDelrin1200_zps999456be.jpg.html)

As per my usual practice, I selected a preload on the knee of the curve, just below the plateau, in this case 4.5 turns out.... I refilled the tank to 3000 psi and shot a string with the following results....

(http://i378.photobucket.com/albums/oo221/rsterne/QB%20on%20HPA/QB79NinjaString1200_zpsbf52d449.jpg) (http://s378.photobucket.com/user/rsterne/media/QB%20on%20HPA/QB79NinjaString1200_zpsbf52d449.jpg.html)

I got 80 shots between 844 and 856 fps, an ES of just 12 fps (1.4%).... and was able to shoot down to 1100 psi before the velocity dropped below 840.... The average was 849 fps (25.5 FPE) at an efficiency of 1.21 FPE/CI.... During shooting the string, I shot 5 shot groups and sighted in the scope in my 20ft. indoor range.... By the time I was done, it was punching group after group in the same place on the target that were only 1/4" across, barely bigger than the pellet.... I can't wait to try this rifle out at longer ranges.... This is just about the perfect velocity to shoot the 15.9 gr. Exact at, putting it right in the middle of it's sweet spot for the Ballistics Coefficient....

This has been an exciting project, and I'm extremely pleased with the final outcome....

Bob
Title: Re: QB79 Ninja - The $200 PCP
Post by: evandj on August 06, 2013, 08:57:30 AM
Great results with a great looking stock to boot.
Title: Re: QB79 Ninja - The $200 PCP
Post by: Froggy. on August 06, 2013, 07:18:32 PM
Remarkable performance at only 1200 psi!
Bob, can you give an estimate of the velocity increase with a 50cc plenum?...I'm busy with a qb 79 bullpup build and will be using a longer tube giving about 50cc plenum.
Title: Re: QB79 Ninja - The $200 PCP
Post by: Ribbonstone on August 06, 2013, 08:05:23 PM
Post has made me appreciate the QB's once again. Think I'm destined to own two more.

As it is, they all run on air.  .177, 5mm, 22, and .25 from 11 foot pounds to 60. 4 HPA’s and two PCP’s.

(http://i157.photobucket.com/albums/t50/ribbonstone/QB%20mods/d5e73d29-252b-4db0-b302-f3d9e06e7f30.jpg) (http://s157.photobucket.com/user/ribbonstone/media/QB%20mods/d5e73d29-252b-4db0-b302-f3d9e06e7f30.jpg.html)

Am going to undo #2 from the left. New (full length) barrel, modded valve, and a 1100PSI tank,a tune it to 20 foot pounds.

And will add a plain jane co2 version, as close to stock as I can stand.
Title: Re: QB79 Ninja - The $200 PCP
Post by: rsterne on August 06, 2013, 09:05:01 PM
Froggy.... Here is a thread that talks about the difference that volume makes in a QB78 or QB79....  http://www.gatewaytoairguns.org/GTA/index.php?topic=21681 (http://www.gatewaytoairguns.org/GTA/index.php?topic=21681)

On 1500 psi and with a valve where the front end was slotted (same valve in both guns), the difference was about 5 FPE.... What happens is that the AVERAGE pressure at the valve seat increases with the larger plenum, so the gun shoots as if you cranked up the regulator setpoint.... The efficiency also increases with the larger plenum, so it's a win-win situation....

Bob
Title: Re: QB79 Ninja - The $200 PCP
Post by: Captain Bravo on August 16, 2013, 04:57:39 PM
I have read other places that a "...Paintball Tank Adapter for QB79" might be required for a 2" tank.  Did you need one for the Ninja hpa setup, or was there enough clearance?
Title: Re: QB79 Ninja - The $200 PCP
Post by: rsterne on August 16, 2013, 06:02:58 PM
Modern paintball CO2 tanks are 2.06" diameter and need an adapter to clear the barrel.... The Ninja tanks are 1.998" OD and clear the barrel just fine....

Bob
Title: Re: QB79 Ninja - The $200 PCP
Post by: Captain Bravo on August 16, 2013, 07:32:06 PM
That is what I was hoping. Thanks Bob
Title: Re: QB79 Ninja - The $200 PCP
Post by: rsterne on August 23, 2013, 10:35:20 PM
I finally had a chance to do some testing outdoors today, so I tested all the pellets scoring "green" in the last tests indoors that I expected to have a decent BC at 25 yards.... I measured the average velocity at the muzzle and at 25 yards, for 5 shots with each pellet, and then used ChairGun3 to calculate the Ballistics Coefficient.... Here are the results....

(http://i378.photobucket.com/albums/oo221/rsterne/QB%20on%20HPA/QBNinja25ydVelocity_zps5fa1aa10.jpg) (http://s378.photobucket.com/user/rsterne/media/QB%20on%20HPA/QBNinja25ydVelocity_zps5fa1aa10.jpg.html)

The groups were sorted as usual, with any group you could cover with a Dime scoring green, any group you couldn't cover with a quarter scoring red, and in between no colour code.... I was surprised that all the JSBs were the only pellets that produced sub-dime sized groups.... and the best of those was the 15.9 gr. Exact Jumbo.... When you look at the JSB Exacts, the heavier the pellet the better the BC, as expected, and this results in a lot more FPE at 25 yards.... However, with the combinaton of good velocity and high BC, plus superb accuracy, I chose the 15.9 gr. as the pellet to use.... After sighting the rifle in 1/4" high at 25 yards, here is a typical 5-shot group....

(http://i378.photobucket.com/albums/oo221/rsterne/QB%20on%20HPA/QB79Ninja001_zps59632639.jpg) (http://s378.photobucket.com/user/rsterne/media/QB%20on%20HPA/QB79Ninja001_zps59632639.jpg.html)

The small squares are 0.1", and the black squares are 0.4", so the C-T-C size of that group is less than 0.25".... I can get 70 shots per fill at 25 FPE, and basically it just keeps dumping them in a ragged hole at 25 yards.... I think we can call this project an unqualified success, and this rifle has earned a place on my "wall of keepers"....

Bob
Title: Re: QB79 Ninja - The $200 PCP
Post by: Mebits on August 24, 2013, 07:50:50 PM
Nice. I love mine, I can tell you.
Title: Re: QB79 Ninja - The $200 PCP
Post by: Rdsail on October 17, 2013, 08:13:03 AM
I finished and installed the stock today....

(http://i378.photobucket.com/albums/oo221/rsterne/QB%20on%20HPA/IMG_3592_zps58f80da4.jpg) (http://s378.photobucket.com/user/rsterne/media/QB%20on%20HPA/IMG_3592_zps58f80da4.jpg.html)

It's a Richard's Microfit Wildcat Thumbhome in Select Grade Black Walnut with Ebony Grip Cap.... beautiful figuring in the grain....

(http://i378.photobucket.com/albums/oo221/rsterne/QB%20on%20HPA/IMG_3595_zps685d0609.jpg) (http://s378.photobucket.com/user/rsterne/media/QB%20on%20HPA/IMG_3595_zps685d0609.jpg.html)

I had to shorten the forearm and inlet it for the tank block and regulator.... The finish is 7 coats of Watco Danish Oil, each coat wet sanded, ending with a white Scothbrite pad of 1200 grit equivalent and then a coat of Dark Minwax.... The scope is a Leapers 3-9 x 32 AO with Sunshade.... The gun weighs 8 lb. 7 oz. as shown.... The Air Stripper is from a Hatsan PCP, I threaded the barrel 1/2"-20 NF to accept it....

It's no longer a $200 PCP, however....

Bob

bob, As always, amazing work. I disappointed that I found this post so late. There are a lot of parallels with my bottled disco and I was building it around the same time.

I looked at this pictures and they look very similar to my disco. One mod that I made that many people comment on is how if fill the gap between the stock and bottle and the barrel. I wen to the office supply store. Bought a black blastic textured folder. I got the heavy plastic. The light plastic does not work as well. then cut out a rectangle. then the openings for the gauge and rounded the two corner by the bottle. It took about 5 minutes to do and it looks it was molded in place.

Just a thought.
Title: Re: QB79 Ninja - The $200 PCP
Post by: bradyman1 on November 18, 2013, 10:42:15 PM
What a fantastic job. Awesome project!
Title: Re: QB79 Ninja - The $200 PCP
Post by: unclejack on November 20, 2013, 02:32:20 PM
I found the larger tank type modification on QB79. In order to install a larger tank, the stock part has been modified as bullpup.

(http://i.imgur.com/yOnyqBr.jpg)
(http://i.imgur.com/Vzoy3DC.jpg)
(http://i.imgur.com/iNF5eZr.jpg)
Title: Re: QB79 Ninja - The $200 PCP
Post by: Gertrude on November 20, 2013, 03:45:49 PM
I found the larger tank type modification on QB79. In order to install a larger tank, the stock part has been modified as bullpup.

(http://i.imgur.com/yOnyqBr.jpg)
(http://i.imgur.com/Vzoy3DC.jpg)
(http://i.imgur.com/iNF5eZr.jpg)

Ok,... now THAT just about takes it as far as it could go! I have been wanting a MM tuned QB79 for quite some time here... And THAT has just pushed me over the edge !
 WOW !
 We need more details on that stock and that build ! That is SWEET !

 MIKE ! ! !
 YOU NEED TO GET SUMMADEEZ STOCKS ! or find out where they can be had !
 IMMAGUNNA have to Figgerout how I can get ONE-A-DEM !
Title: Re: QB79 Ninja - The $200 PCP
Post by: RMM on November 21, 2013, 12:25:45 PM


Ok,... now THAT just about takes it as far as it could go! I have been wanting a MM tuned QB79 for quite some time here... And THAT has just pushed me over the edge !
 WOW !
 We need more details on that stock and that build ! That is SWEET !

 MIKE ! ! !
 YOU NEED TO GET SUMMADEEZ STOCKS ! or find out where they can be had !
 IMMAGUNNA have to Figgerout how I can get ONE-A-DEM !

Click on the link at the bottom of unclejack's pics and your bullpup fantasies will be fulfilled.  ;)  You will have to run the page through a translator but it's well worth the visit..
Title: Re: QB79 Ninja - The $200 PCP
Post by: chuckinohio on November 21, 2013, 01:41:19 PM
  Any thoughts on using a 17ci Rap4 tank to get a higher shot count before refilling?

  http://www.rap4.com/store/paintball/p/015194/hpa-17ci-3000psi-compressed-air-tank-empty (http://www.rap4.com/store/paintball/p/015194/hpa-17ci-3000psi-compressed-air-tank-empty)

 Its specs say that it is 1.938 in diameter, and fitted with the Ninja SHP regulator, it ought to do the trick as well correct?

 
Title: Re: QB79 Ninja - The $200 PCP
Post by: rsterne on November 21, 2013, 04:33:12 PM
Yep, slightly more muzzle heavy.... and by the time you buy the tanks and regulators separately, will likely cost more.... Your shot count, similarly tuned, should increase by 17/13 = 30%.... That would take my gun from 80 shots to about 105 shots per fill.... Is that worth it, only you can decide....

Bob
Title: Re: QB79 Ninja - The $200 PCP
Post by: chuckinohio on November 21, 2013, 07:24:15 PM
  The 13ci set up from your OP is definitely the way to go as far as cost and ease of procurement.
  I suppose that if one just had to have the extra 30% increase in volume, the extra $100 bones for a 17ci tank is a soft enough blow.

  Thanks for ALL of the great info in this thread, it's got me thinking that PCP isn't an expensive proposition after all.
Title: Re: QB79 Ninja - The $200 PCP
Post by: Geoff on November 21, 2013, 07:47:03 PM
tagged to check back and read this thread.

one think i will look for is ... this is ~200$ .. a used disco is ~200$ .. either one have a leg up on the other ?  if this was mentioned, apologies as i will be reading the thread tomorrow.
Title: Re: QB79 Ninja - The $200 PCP
Post by: nervoustrigger on November 21, 2013, 09:32:56 PM
If you can do the work to the QB to bring up the power level, you'll have:

1.  more shots per fill (4x as many?)
2.  consistent shots (the benefits of regulated air pressure)
3.  better trigger

I realize that first "if" is a big one for a lot of folks but for a tinkerer, the QB platform is a dream.
Title: Re: QB79 Ninja - The $200 PCP
Post by: Rdsail on November 21, 2013, 09:39:50 PM
I get more than that on my disco. It just cost more and the platform in a better IMO. endless mods. I still thinking of addend a bolt less probe and longer barrel
Title: Re: QB79 Ninja - The $200 PCP
Post by: woogie_man on November 21, 2013, 09:49:28 PM
Question about the tank drop part.....are you able to butt that right up to the valve?  Our what amount of space would be needed?
Title: Re: QB79 Ninja - The $200 PCP
Post by: Ribbonstone on November 21, 2013, 10:47:24 PM
For power, the more space between valve and tank, the better.
Title: Re: QB79 Ninja - The $200 PCP
Post by: woogie_man on November 22, 2013, 03:57:06 AM
Ok....

 Still trying to decide if I want to go this route or use the 2240 as a base for a compact little build.
Title: Re: QB79 Ninja - The $200 PCP
Post by: Ribbonstone on November 22, 2013, 06:17:54 PM
To add to the confusion, you could HPA a Crosman.  Will need to swap valves for a bulk fill valve and add secure that valve a little more solidly, but the same tank block works.

Made this one for my Nephew.

(http://i157.photobucket.com/albums/t50/ribbonstone/crosman/DSCF2568-1.jpg) (http://s157.photobucket.com/user/ribbonstone/media/crosman/DSCF2568-1.jpg.html)


Title: Re: QB79 Ninja - The $200 PCP
Post by: Geoff on November 22, 2013, 06:20:05 PM
one could also go HIPAC for 85$ on their crosman.  if not for having to buy a pump, i would have tried one in mine
Title: Re: QB79 Ninja - The $200 PCP
Post by: toine on December 24, 2013, 09:50:17 PM
To add to the confusion, you could HPA a Crosman.  Will need to swap valves for a bulk fill valve and add secure that valve a little more solidly, but the same tank block works.

Made this one for my Nephew.

(http://i157.photobucket.com/albums/t50/ribbonstone/crosman/DSCF2568-1.jpg) (http://s157.photobucket.com/user/ribbonstone/media/crosman/DSCF2568-1.jpg.html)

Hey Ribbonstone, seeing as Flying Dragon is no longer selling QBs, could you post some more details on this build? Thanks.
Title: Re: QB79 Ninja - The $200 PCP
Post by: Ribbonstone on December 25, 2013, 02:27:24 AM
Nothing complicated.

2250 tube
bulk fill valve (believe it's an old "boss")
Qb79 tank block
tube cut/drilled for tank block mounting
13ci HPA tank (that one is an 850psi output tank)
24" barrel cut to 20" (just long enough to allow the TKO to mount without touching the tank)

Used a brass RAP4 on/off between tank and block

They make paintball stock adaptors now. When i made that one, lathed the paintball stock's metal fitting to the same size as a Crosman end cap, drilled and tapped it, and recessed  it for the rear of the hammer spring.  Way too much work, get the adaptor.
Title: Re: QB79 Ninja - The $200 PCP
Post by: rsterne on December 25, 2013, 12:57:49 PM
If you're after lots of power, don't cut the tube too short, in fact better to start with a 2260 tube, or you will end up in the same boat as with a QB79 where you are fighting against too small a plenum volume between the regulator and valve.... For low-medium powered guns, the shortness may be worth it, however....

Bob
Title: Re: QB79 Ninja - The $200 PCP
Post by: rewinder on March 08, 2014, 05:47:49 PM
Well I'd like to report on my efforts to duplicate your fine work Bob. I started with an older, used QB79, I just bought, that came with a new SHP ninja tank, rap4 on/off/gauge valve and  arrrowman repeater breech kit all installed. It looks to be fitted with a MM tuned valve. and an AJ muzzle beautification.

The SHP is stock, I guess, it reads about 1200 on the rap4 gauge, a better gauge would probably be in order.

As received it shot 760fps, the previous owner said it would do 760 for about 60 rounds, I found that to be right about correct, then i ripped it apart.

1st I ported the barrel to #20 drill, It already had a pointed bolt from the repeater kit. When I assembled it I used a crosman 22xx rubber TP ring.It had a plastic water line seal before.

I removed the piercing pin in the valve and shortened the aluminum tube some, made a valve spring standoff and milled wider slots on the OD. Didn't do the maxi-valve thing.

I put 2 more tank block screws ahead of the original ones, and used 8-32 cap screws.

Lastly I made up a RVA, after converting to cock on open ( drilled a new hole in the hammer, about .3" rear of the original one. put a .75 l x 3/4" OD spacer behind the cocking pin  for the RVA to adjust the preload.

Reassembled and tried it out

I started from weak preload and went up by turning the RVA in, till i got max fps, then backed it out 1/2 turn or so, max was around 835fps, i lowered it to 820. happy with that! Didn't see how long a string i could get at the setting yet, will do it soon.

Then I twisted on a full 9oz co2 tank and from the same RVA setting, walked it out till the fps started to drop. The tank and gun were 58-60* at most, since I was in my cold basement. The max on co2 was 637 average at the previous hpa setting, I lowered it by about 15 fps thinking I was on the "knee" then.  It only took a turn and a half ( 10-32 screw)  So now I can use both fuels and be somewhat  efficient on either, by slight adjustment.

next I'll mount the scope and try different pellets. I had a ball doing this, and thanks to you Bob, it was easy!!!!

I'd post a pic,but everyone knows that a qb79 looks like. The AJ muzzle thingi is 1 1/2 X 10".









Title: Re: QB79 Ninja - The $200 PCP
Post by: rsterne on March 08, 2014, 07:01:27 PM
Glad it worked out for you.... congrats !!!

Bob
Title: Re: QB79 Ninja - The $200 PCP
Post by: rewinder on March 08, 2014, 08:58:54 PM
Thanks Bob,I'm just a copy cat, you're the innovator!

I forgot to mention, I found the hammer spring preloaded with 2 common washers , on the cocking block pin, and I didn't put them back when i reassembled it---- should I put them back? Or wait and see , but how would I know if they are needed?

thnanks
Title: Re: QB79 Ninja - The $200 PCP
Post by: rsterne on March 08, 2014, 10:26:03 PM
Shoot a "power curve" using the preload adjuster you made.... Set it up on the knee of the curve.... Don't use the shims unless you can't get enough preload....

Bob
Title: Re: QB79 Ninja - The $200 PCP
Post by: rewinder on March 08, 2014, 11:05:09 PM
Ok that's what I planned to do when i get some free time and and warmer weather for plotting on co2 also.
If i could get my wife out of the house when I'm not working, I could just open up a window haha.
Title: Re: QB79 Ninja - The $200 PCP
Post by: rewinder on March 10, 2014, 07:28:30 PM
I snuck some time at work to fool a bit with the 79, Iswapped out apoppet I had that seemed to have a harder seat, it was white (delrin maybe?) and had a tapered brass body too, i opened the brass part of the valve some on the lathe, and lubed up the hammer, & reassembled.

Since daylight savings is here, it was light enough to use the crony, the hpa velocity didn't change much ( max  848, adjusted back to 825), but the co2 did. it maxed out at 665 vs 637 the last time (still around 60 degrees) . I'm adjusting the RVA by screwing it in to find max, then dropping it back  about 15fps to get on the knee.  This time I ran out of increase adjustment, cause I couldn't cock it  (this is on co2 now, I had no problem on air finding the knee). Maybe I'm coil locking the hammer spring on co2?? I did put 2 common washers behind the spring this time.

here's a picture (I hope it gets attached!) with the huge lcd and repeater breech,

Next up is to shovel off the back deck and set up the bench,sight in the scope.

The co2 will have to wait for warmer weather,, but now i can practice in the cold with air

Any one have any suggestions to enhance this project?? I really don't mind tearing it down, using the 2240 TP rubber seal ring makes life easy, I can use it over and over it seems
Title: Re: QB79 Ninja - The $200 PCP
Post by: rsterne on March 10, 2014, 09:12:26 PM
You say you can't find the maximum velocity on CO2.... that is VERY strange, as you should need a lot less hammer spring tension than on air, and the colder it is, the less you will require to find the max. as the pressure is lower.... It is possible you can't find the knee because you can't screw it OUT far enough?.... that would be more likely....

Bob
Title: Re: QB79 Ninja - The $200 PCP
Post by: rewinder on March 10, 2014, 09:30:53 PM
Ya know I think you ar e right, I was in a hurry, supper was ready and wife was impatient. I just wrote down a couple of numbers and went up stairs.
 At my age ya get excited, distracted, then ya mix things up.

I need an hour or so with no interruptions and a pad of paper! Any how, I'm happy with it and won't open it up again till I do more testing.
EDIT:
sitting here thinking about is now, i adjusted with air first, swapped tanks reloaded mag and wife called down to me for supper--- distracted , i shota few on co2, all the while screwing IN the RVA lol wrote down the co2 #'s and went up stairs--- i just now remembered i forgot to shut off the chrony. It ain't pretty gettin old

2nd edit-this one is correct:

Looked at my 79 and the ninja is on it, so i tested on co2 FIRST, found the knee at fps listed above

THEN I put the ninja on and in screwing the adjuster in, I got to  around 838, wife called as i got to point of not being able to cock, backed off a bit, went upstairs. I posted thinking co2 was the last run on chrony, when it really was air.

That makes sense now haha. So maybe 838 is the top of the curve, I think it is sitting here now.

going to watch Bill O and forget my embarrassment 




thanks Bob
Title: Re: QB79 Ninja - The $200 PCP
Post by: rewinder on March 15, 2014, 06:49:28 PM
I ran a fully charged ninja today to get a shot count.

With tinned  22 CHP's
Full ninja SHP, reg is stock, not shimmed. But the rap4 valve gauge reads 1200, and creeps to 1300 after a few min.

 adjusted RVA down to 820, got about 62 shots -- was hoping for 80!
All shots deviated only 12 fps max.
before the reg was bottomed out, I put 2 15.9 exact's thru for fun, and got 780fps.

I was hoping for more shots, the velocity is OK my me.

So I'm not near as efficient as yours Bob, maybe I need to increase tube volume by chopping the valve's aluminum off like you did.
How about boring out the drop block forward some (from tube side) to add volume?
Maybe make a solid delrin valve poppet on the old stem--(should a new delrin valve's sealing face be 90 degrees to the stem, or angled concave or convex?)

Any suggestions appreciated!

It's fun fooling with this thing.



BTW, on co2 it maxed out at 662fps, but the co2 tank and QB were about 55deg
Title: Re: QB79 Ninja - The $200 PCP
Post by: sr1sws on March 18, 2014, 07:13:16 PM
Question... Flying Tiger is not selling QBs at this time.  Found them at ^&$@_=s.  Archer says you need their paintball tank adapter to keep the tank away from the barrel.  Have the QB79s changed dimensions to require the adapter or is the vendor just working to sell a $32 chunk of metal?

Thanks!
Steve
Title: Re: QB79 Ninja - The $200 PCP
Post by: nervoustrigger on March 18, 2014, 11:42:47 PM
Flying Tiger is not selling QBs at this time.

Crouching Tiger...Flying Dragon?  ;)

Found them at ^&$@_=s.  @=S+S%^$# says you need their paintball tank adapter to keep the tank away from the barrel.  Have the QB79s changed dimensions to require the adapter or is the vendor just working to sell a $32 chunk of metal?

If using a 13ci Ninja brand tank, you do not need anything special to install it on a QB79.  The standard issue tank block works fine and usually leaves 1/8" of clearance between the tank and barrel. 

Some other brands of 13ci paintball tanks are a little larger diameter and may not fit.
Title: Re: QB79 Ninja - The $200 PCP
Post by: sr1sws on March 19, 2014, 08:36:44 AM
Flying Tiger is not selling QBs at this time.

Crouching Tiger...Flying Dragon?  ;)

Found them at ^&$@_=s.  @=S+S%^$# says you need their paintball tank adapter to keep the tank away from the barrel.  Have the QB79s changed dimensions to require the adapter or is the vendor just working to sell a $32 chunk of metal?

If using a 13ci Ninja brand tank, you do not need anything special to install it on a QB79.  The standard issue tank block works fine and usually leaves 1/8" of clearance between the tank and barrel. 

Some other brands of 13ci paintball tanks are a little larger diameter and may not fit.

Dragons, tigers... one of those Asian motifs  ;D

Thanks for the info, $30+ can buy a lot of pellets.

I noticed the vendor name was "blotted out"... did I unknowingly violate a forum rule?... no vendor references?  Or is there another reason?

Many thanks to all, have a happy Hump Day!

Steve
Title: Re: QB79 Ninja - The $200 PCP
Post by: sr1sws on March 19, 2014, 10:53:16 PM
And another questions... how loud is the QB79 running on HPA?  As loud as a Disco without an LDC?

Steve
Title: Re: QB79 Ninja - The $200 PCP
Post by: rsterne on March 20, 2014, 01:28:11 AM
At similar power levels, the report is about the same as a Disco without LDC.... but it can vary quite a bit depending on how it's tuned, just as a Disco is about twice as loud on the first shot as the last shot....

Bob
Title: Re: QB79 Ninja - The $200 PCP
Post by: sr1sws on March 20, 2014, 08:40:49 AM
At similar power levels, the report is about the same as a Disco without LDC.... but it can vary quite a bit depending on how it's tuned, just as a Disco is about twice as loud on the first shot as the last shot....

Bob

Thanks Bob.  Just trying to figure the TCO of going this route.  Looks like the Umax compensator would be more affordable than a TKO Level V for a QB.

Thanks for publishing this route (QB79 + Ninja SHP).  If I had seen this a few weeks ago, I might have gone this route rather than my Disco... but maybe I'll do both.

Have a great day!
Steve
Title: Re: QB79 Ninja - The $200 PCP
Post by: plinker81366 on April 01, 2014, 11:14:24 PM
philippine version of the conversion

(http://i1353.photobucket.com/albums/q674/plinker81366/10154959_10152345404874265_579156495_n_zps52760c25.jpg)
Title: Re: QB79 Ninja - The $200 PCP
Post by: westtexasrancher on April 02, 2014, 06:15:59 PM
Now that is dang cool.
Title: Re: QB79 Ninja - The $200 PCP
Post by: plinker81366 on April 03, 2014, 07:58:53 AM
Now that is dang cool.
yep the mahogany stock s great.. whats nice is at 1200 reg output.. the power is bordering the 30 fpe mark at 1.06 efficiency..
Title: Re: QB79 Ninja - The $200 PCP
Post by: ev-in-az on May 14, 2014, 07:44:02 PM
Flying Tiger is not selling QBs at this time.

Crouching Tiger...Flying Dragon?  ;)

Found them at ^&$@_=s.  @=S+S%^$# says you need their paintball tank adapter to keep the tank away from the barrel.  Have the QB79s changed dimensions to require the adapter or is the vendor just working to sell a $32 chunk of metal?

If using a 13ci Ninja brand tank, you do not need anything special to install it on a QB79.  The standard issue tank block works fine and usually leaves 1/8" of clearance between the tank and barrel. 

Some other brands of 13ci paintball tanks are a little larger diameter and may not fit.

The barrel has to be removed to install the Ninja tank. Clearance with the barrel is not an issue. I use the paintball adapter along with a mini fill valve which allows removal of the Ninja tank and and a CO2 tank to be installed. CO2 is not a good option here in the hot desert in the summer.
Title: Re: QB79 Ninja - The $200 PCP
Post by: ev-in-az on May 14, 2014, 07:45:53 PM
Wish my QB79 was that good looking -- very nice.
Title: Re: QB79 Ninja - The $200 PCP
Post by: 728b on May 21, 2014, 12:43:46 PM
I have a question for all. I have just finished phase 2 of the conversion. I was surprised that my stock gun was averaging 649 fps before I did any thing to it using CPHP 14.3. I read where rsterne after Phase 2 added ~150 fps simply by drilling out the transfer port and the bolt probe and adding the new seal. (I don't think I missed anything) Anyway I did those things to my QB and went from 649 fps to 705 fps average. The only difference is that I use the poly-tubing as I did not have a Discovery seal. 

What am I missing? I was thinking I should be at least somewhere around 740-750.
Title: Re: QB79 Ninja - The $200 PCP
Post by: nervoustrigger on May 21, 2014, 01:38:18 PM
Ah, so many little variables! ;)

One may be a difference in regulator setpoint between yours and his.

The poly tube might be leaking slightly.  Have you tried the tissue test?

Might need more hammer strike.  Try adding a 0.1" spacer on the hammer spring.  Washers or a small piece cut from the body of a plastic ink pen will work.
Title: Re: QB79 Ninja - The $200 PCP
Post by: sr1sws on May 21, 2014, 03:37:36 PM
I also posted this in another semi-related thread, so apologies to those reading this twice:

Other than "the vendor who shall not be named", is there another source for the QB79?  Flying Dragon appears to no longer carry them.  Google wasn't helpful - or maybe I didn't hold my mouth quite right :)

Thanks!
Steve
Title: Re: QB79 Ninja - The $200 PCP
Post by: 728b on May 21, 2014, 04:00:03 PM
Ah, so many little variables! ;)

One may be a difference in regulator setpoint between yours and his.

The poly tube might be leaking slightly.  Have you tried the tissue test?

Might need more hammer strike.  Try adding a 0.1" spacer on the hammer spring.  Washers or a small piece cut from the body of a plastic ink pen will work.

You are right I had not thought about those variables. I would guess that even a small difference in the spring could make a significant difference. But I would guess that the regulator most likely could be the culprit. If there is one. I have not tried the tissue test but will asap.

I still don't understand why I would have a high initial fps in the stock configuration and that same configuration only adding 50 fps when I opened up the transfer and probe.

It is obvious I still have a lot to learn and I am thankful to ya'll for sharing your knowledge. I still can't get my weak mind around what exactly to do the valve.

I was just thinking as I was re-reading this response. The barrel is recessed to accept the transfer seal but the breech is not.  I also did not open up the transfer opening in the breech itself.
Title: Re: QB79 Ninja - The $200 PCP
Post by: rsterne on May 21, 2014, 04:21:06 PM
If your initial (unmodified) velocity was greater, you will gain less than I did from the Stage 1 mods.... If you ended up roughly in the same place, that is as it should be.... If you are a little low, it's likely the regulator setpoint....

Bob
Title: Re: QB79 Ninja - The $200 PCP
Post by: 728b on May 21, 2014, 04:50:08 PM
If your initial (unmodified) velocity was greater, you will gain less than I did from the Stage 1 mods.... If you ended up roughly in the same place, that is as it should be.... If you are a little low, it's likely the regulator setpoint....

Bob
That make sense to me. Now I have to decide if I want to tear into the reg. ;)
Title: Re: QB79 Ninja - The $200 PCP
Post by: 728b on May 21, 2014, 04:51:52 PM
Also, If I shim the spring with a washer will I be moving toward wasting more air and loosing efficiency?

Again thanks for your help.
Title: Re: QB79 Ninja - The $200 PCP
Post by: nervoustrigger on May 21, 2014, 06:43:43 PM
Steve, apparently Voldemort (he who shall not be named) or an affiliate like eabco.com are the only sources at this time.  It's a bummer because Mike is a one-in-a-million kind of guy and I try to give my business to him whenever possible.

728b, shimming the hammer spring will indeed increase CO2 usage.  Whether it is wasted depends on the results you get over the chrony.  If velocity doesn't improve, you're wasting gas.  If velocity goes up, you know you made a step in the right direction. 

Ultimately you want to fine tune the hammer strike to optimize the balance of velocity and CO2.  At this point though, we are just trying to see if you have some unclaimed fps under the hood.
Title: Re: QB79 Ninja - The $200 PCP
Post by: 728b on May 22, 2014, 04:19:18 PM
Just for clarification the gun is on HPA. I'm sure the principle remains the same for shimming.

As you suggested I did the tissue test and did have some air escaping at the transfer port. I need to get the Discovery seal as suggested earlier.

Title: Re: QB79 Ninja - The $200 PCP
Post by: rsterne on May 23, 2014, 12:14:09 AM
I got a chance to go gopher hunting with my QB79 Ninja HPA today.... It's deadly out to 40 yards, the longest shot I took.... 20 FPE remaining at that range....

Bob
Title: Re: QB79 Ninja - The $200 PCP
Post by: sr1sws on May 23, 2014, 08:42:55 AM
I got a chance to go gopher hunting with my QB79 Ninja HPA today.... It's deadly out to 40 yards, the longest shot I took.... 20 FPE remaining at that range....

Bob

Very nice.  I may get one yet :)

Steve
Title: Re: QB79 Ninja - The $200 PCP
Post by: WECSOG on November 30, 2015, 12:05:34 PM
I'm getting a QB79 for Christmas! I just re-read this entire thread, and figured it might be worthwhile to dredge it back up again.
In case anyone is unaware, Airgun Depot has them now (under the Beeman banner) and today for Cyber Monday they have 11% off. That makes the QB79 just under $95, and free shipping.

As much as I enjoy tinkering with my Crosmans, this thread and others on the QB have been a constant siren song. Time to scratch that itch.
Title: Re: QB79 Ninja - The $200 PCP
Post by: Chemdawg on November 30, 2015, 02:08:12 PM
Now I'm just curious.  Since this is relatively cheap, I'm interested.  After dropping almost 600 bucks on my newest pistol, I think this might be in the near future.  So.  Does that ninja regulator screw right on there without any modifications or additions?  Purchase this gun and that Ninja 3000psi/13ci tank/shp pro regulator, screw it on and your ready to go?
Title: Re: QB79 Ninja - The $200 PCP
Post by: huklbery on November 30, 2015, 02:16:04 PM
Now I'm just curious.  Since this is relatively cheap, I'm interested.  After dropping almost 600 bucks on my newest pistol, I think this might be in the near future.  So.  Does that ninja regulator screw right on there without any modifications or additions?  Purchase this gun and that Ninja 3000psi/13ci tank/shp pro regulator, screw it on and your ready to go?

Not sure, the new ones have a tucked in nipple so it may spin and clear.  The pro also has an orientation band that allows you to spin the bottle separate from the cap thread.   Otherwise you can simply remove the barrel or the block and screw it in.

Off the shelf they had 800 & 1100 psi preset regulators, I used an 1100 now on several CO2 guns and have had no issue with valve lock.  Air just shoots so much cleaner and is drama free in comparison to CO2, a great upgrade. 
Title: Re: QB79 Ninja - The $200 PCP
Post by: WECSOG on November 30, 2015, 02:44:31 PM
I'll probably never bother with co2 in mine. Now I just have to find the bottle with SHP reg in stock!
I wonder how well it would perform power and shot count wise with Bob's mods and tuning and a standard 850 psi reg? I would be happy with 12 fpe, especially if it gave a high shot count.
Title: Re: QB79 Ninja - The $200 PCP
Post by: nervoustrigger on November 30, 2015, 03:08:57 PM
If memory serves, I was getting about 18fpe in .22 cal on 850psi with a QB78 so I don't think you'd have any trouble getting 12fpe even with the shorter tube and in .177, assuming that's the caliber you have in mind.

For good efficiency, definitely do the RVA mod.  Far and away the easiest way to tweak for power vs shot count.  You may also benefit from lightening the hammer but my advice is start with the RVA and do the hammer work afterwards if you aren't happy with the efficiency. 
Title: Re: QB79 Ninja - The $200 PCP
Post by: WECSOG on November 30, 2015, 07:50:21 PM
Thanks, Jason. Yeah, my intention is to do the top-end mod Bob describes, make an RVA with a jam nut (which is how I usually do it) and do the valve front-end mod as both you and Bob describe. Your build thread was also a great incentive to get my own QB79. I have read it in its entirety more than once, and I read it again this morning.

My QB is .22 caliber. AD just sent notification that it has shipped.
Title: Re: QB79 Ninja - The $200 PCP
Post by: nervoustrigger on December 01, 2015, 12:17:43 AM
Thanks Tracy, I always like hearing when one of my projects inspires others to take up something similar.

Seeing as how you're aiming for 12fpe in .22 cal, I suspect you will indeed benefit from lightening the hammer.  That energy level in a free-flowing rifle will require just the tiniest sip of air so a sharp tap on the valve stem with a light hammer should do the trick and minimize the opportunity for any bouncing that might otherwise waste air.

Definitely stick with the 850psi setpoint for this type of tune.  A SHP bottle at 1100psi is overkill and would only serve to make things more difficult to tame the tune down to 12fpe.

Shot count should border on the absurd.  An efficiency of only 1.25 will yield 200 shots per fill and it's not unreasonable to expect you might hit 250.
Title: Re: QB79 Ninja - The $200 PCP
Post by: WECSOG on December 01, 2015, 01:26:35 AM
I'm liking the sounds of that! I'll take your advice, Jason, and stick with 850. Seems that will also help shot count in that it has a ways further to go before it hits the set point.
Title: Re: QB79 Ninja - The $200 PCP
Post by: rsterne on December 01, 2015, 12:41:47 PM
At 850 psi you will have to significantly REDUCE the hammer strike or you will be wasting a huge amount of air.... Once you have the gun up and running, read my threads on tuning regulated PCPs....  http://www.gatewaytoairguns.org/GTA/index.php?topic=74919. (http://www.gatewaytoairguns.org/GTA/index.php?topic=74919.)

Bob
Title: Re: QB79 Ninja - The $200 PCP
Post by: WECSOG on December 01, 2015, 01:40:22 PM
Thanks, Bob. Yeah, I know I'll have to reduce the hammer strike. I will probably swap in a lighter hammer spring and perhaps a lighter hammer as well, and make an RVA so I can easily adjust it.
Title: Re: QB79 Ninja - The $200 PCP
Post by: Tweeter on December 01, 2015, 04:36:48 PM
All this talk about QB's and now I have one on the way...  A couple questions
  I plan to tear it down completely to de burr and polish everything, also to do some valve work.  Can anyone tell my the o ring sizes for the tank block and the valve?  What is the best o ring material when using hpa?
  I will be running the 13ci Ninja pro with 1100psi reg, should I replace the tank block screws?  Thanks guys!
Title: Re: QB79 Ninja - The $200 PCP
Post by: nervoustrigger on December 01, 2015, 04:55:38 PM
-113 for the valve, -016 for the tank block (or metric 19mm OD x 2mm CS).  These are static O-rings holding air so Buna-N works great and they are inexpensive.  Durometer of 70A is good but the more commonly available 50A should work fine too.

Yes, definitely replace the tank block screws with some good quality M4 x 10mm socket head cap screws.  Bear in mind, however, that you don't need to crank them down super tight, just snug. All their load is in shear. 
Title: Re: QB79 Ninja - The $200 PCP
Post by: pllagunos on December 01, 2015, 05:04:11 PM
Would you recommend replacing the stock o-rings and tank block screws with better ones if I am using a 850psi Ninja tank?
Title: Re: QB79 Ninja - The $200 PCP
Post by: nervoustrigger on December 01, 2015, 05:38:56 PM
I suggest always replacing the screws because it's so inexpensive and if you own the rifle long enough, eventually the regulator will fail or the seat will creep and there will be >1500psi against them for some length of time until the 1.8k burst disk ruptures.

Regarding the stock O-rings, seldom will they survive disassembly due to burrs left from manufacture so attempting to reuse them invariably results in a frustrating hissing sound from your newly-assembled rifle that you're anxious to try out.  So yeah, plan to replace those too ;D
Title: Re: QB79 Ninja - The $200 PCP
Post by: sr1sws on December 01, 2015, 05:48:27 PM
I suggest always replacing the screws because it's so inexpensive and if you own the rifle long enough, eventually the regulator will fail or the seat will creep and there will be >1500psi against them for some length of time until the 1.8k burst disk ruptures.

Regarding the stock O-rings, seldom will they survive disassembly due to burrs left from manufacture so attempting to reuse them invariably results in a frustrating hissing sound from your newly-assembled rifle that you're anxious to try out.  So yeah, plan to replace those too ;D

+1 on "eats original o-rings upon dis-assembly".  Even after de-burring, mine still manages to nick some.  Just replaced a barrel o-ring this afternoon.

Steve
Title: Re: QB79 Ninja - The $200 PCP
Post by: pllagunos on December 01, 2015, 05:49:52 PM
 ;D when I get mine I will try it bone stock with the regulator at 850psi, after that I think I am going to do the complete tune you did in your thread (amazing btw) however I will just attempt 19fpe since it is a .177
Title: Re: QB79 Ninja - The $200 PCP
Post by: Tweeter on December 01, 2015, 06:19:25 PM
When I tuned my qb78 I polished the inside of the tube more or less to reduce the chance of nicking the valve o ring when I re assembled it.  Should this be done on the 79 also?  And does it get a very light coat of silicone grease?
Title: Re: QB79 Ninja - The $200 PCP
Post by: Airsnipe on December 01, 2015, 06:58:49 PM
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.
Title: Re: QB79 Ninja - The $200 PCP
Post by: pllagunos on December 01, 2015, 07:04:25 PM
You can't buy a regulator set above 1100 psi however you can adjust it yourself with an output tester and some belleville washers, take a look at this link: http://www.gatewaytoairguns.org/GTA/index.php?topic=49648.msg469843#msg469843 (http://www.gatewaytoairguns.org/GTA/index.php?topic=49648.msg469843#msg469843)

Also you don't want to regulate it to 3000 psi, I am not sure it would even work
Title: Re: QB79 Ninja - The $200 PCP
Post by: huklbery on December 01, 2015, 07:06:50 PM
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.

The bottle is 3k so that would be remove the guts I imagine. Past that it use different combination of wave washers to give a static output pressure not an adjustable one on the fly so to speak.
Title: Re: QB79 Ninja - The $200 PCP
Post by: sr1sws on December 01, 2015, 07:09:48 PM
When I tuned my qb78 I polished the inside of the tube more or less to reduce the chance of nicking the valve o ring when I re assembled it.  Should this be done on the 79 also?  And does it get a very light coat of silicone grease?

It's really the holes and slots that have burrs that cut o-rings.  Remove them and you should be good.  I don't see a reason to try to polish the entire interior of the tube.  Silicone grease = goodness for o-rings.  Apply before assembly.

Steve
Title: Re: QB79 Ninja - The $200 PCP
Post by: BigTinBoat on December 01, 2015, 09:31:58 PM
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.

Here's a "non-adjustable" set to 2900

http://www.paintball-discounters.com/ninja-airgun-only-4500-psi-spa-regulator-2900-output/ (http://www.paintball-discounters.com/ninja-airgun-only-4500-psi-spa-regulator-2900-output/)
Title: Re: QB79 Ninja - The $200 PCP
Post by: GarthThomas on December 01, 2015, 10:09:50 PM
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.
Title: Re: QB79 Ninja - The $200 PCP
Post by: GarthThomas on December 01, 2015, 10:10:53 PM
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. I was under the impression that anything over 1800psi was dangerous.
Title: Re: QB79 Ninja - The $200 PCP
Post by: sr1sws on December 01, 2015, 10:31:01 PM
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
Title: Re: QB79 Ninja - The $200 PCP
Post by: Airsnipe on December 01, 2015, 10:37:31 PM
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.
Title: Re: QB79 Ninja - The $200 PCP
Post by: huklbery on December 01, 2015, 10:46:55 PM
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. 
Title: Re: QB79 Ninja - The $200 PCP
Post by: sr1sws on December 01, 2015, 10:48:12 PM
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
Title: Re: QB79 Ninja - The $200 PCP
Post by: Ribbonstone on December 01, 2015, 10:57:02 PM
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.
Title: Re: QB79 Ninja - The $200 PCP
Post by: pllagunos on December 01, 2015, 11:19:03 PM
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
Title: Re: QB79 Ninja - The $200 PCP
Post by: nervoustrigger on December 01, 2015, 11:25:06 PM
Unfortunately there are no off-the-shelf burst disks between 1.8k and 3k that anyone here has ever found.
Title: Re: QB79 Ninja - The $200 PCP
Post by: pllagunos on December 02, 2015, 12:06:50 AM
So how do you regulate to 1.5k without the disc failing?
Title: Re: QB79 Ninja - The $200 PCP
Post by: nervoustrigger on December 02, 2015, 12:43:08 AM
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.

Title: Re: QB79 Ninja - The $200 PCP
Post by: rsterne on December 02, 2015, 12:45:08 AM
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
Title: Re: QB79 Ninja - The $200 PCP
Post by: Ribbonstone on December 02, 2015, 06:32:15 PM
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.
Title: Re: QB79 Ninja - The $200 PCP
Post by: BigTinBoat on December 02, 2015, 11:42:07 PM

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

Title: Re: QB79 Ninja - The $200 PCP
Post by: WECSOG on December 03, 2015, 12:03:43 AM
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.
Title: Re: QB79 Ninja - The $200 PCP
Post by: Ribbonstone on December 03, 2015, 07:49:03 AM
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.
Title: Re: QB79 Ninja - The $200 PCP
Post by: WECSOG on December 08, 2015, 08:42:16 PM
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.
Title: Re: QB79 Ninja - The $200 PCP
Post by: huklbery on December 08, 2015, 09:30:12 PM
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.
Title: Re: QB79 Ninja - The $200 PCP
Post by: WECSOG on December 09, 2015, 11:27:55 AM
What kinda performance do you get from your AS 392?
Title: Re: QB79 Ninja - The $200 PCP
Post by: Tweeter on December 13, 2015, 01:48:27 PM
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.
Title: Re: QB79 Ninja - The $200 PCP
Post by: wiffle32 on December 14, 2015, 11:12:52 AM
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.
Title: Re: QB79 Ninja - The $200 PCP
Post by: Tweeter on December 14, 2015, 11:16:52 AM
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.
Title: Re: QB79 Ninja - The $200 PCP
Post by: wiffle32 on December 14, 2015, 11:29:34 AM
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.

Outstanding.
Maine Maritime Academy graduate - 2007 - No shortage of emery cloth in my garage.

It DOES appear, however, that AirgunDepot has a shortage of .22 cal QB79's
Title: Re: QB79 Ninja - The $200 PCP
Post by: Tweeter on December 14, 2015, 02:47:41 PM
I am in the process of tuning one up for myself now though I will never get it even close to the qb79 I have that nervoustrigger tuned up.  My goal was to reach 20fpe with JSB 18.1's and with some small valve mods and a good deburring/polishing it seems I have made it.  I shot a full string over the chrony from 3000psi to about 1100psi with JSB 18.1's and got a low of 702 and a high of 714 for 58 shots.  I think with some tweaking I could get a few more shots but I'm happy for now. I love these regulated ninja tanks!
  The barrel already shows promise but it has some crud in it.  I am waiting for an order from brownells now so I can try to polish the bore.  Then it's on to mounting the scope and seeing how it ends up.
Title: Re: QB79 Ninja - The $200 PCP
Post by: indianarifleman92 on December 14, 2015, 09:36:45 PM
Bob is defiantly an enabler, I just got my first pcp "discovery .22" about 2 months ago. After reading about his qb79 ninja, I'm getting a 13ci ninja tank for Christmas and buying a qb79 soon! :D
Title: Re: QB79 Ninja - The $200 PCP
Post by: Tater on December 14, 2015, 10:00:58 PM
Bob is defiantly an enabler, I just got my first pcp "discovery .22" about 2 months ago. After reading about his qb79 ninja, I'm getting a 13ci ninja tank for Christmas and buying a qb79 soon! :D

You've just crossed over the point of no return.
Title: Re: QB79 Ninja - The $200 PCP
Post by: WECSOG on December 14, 2015, 10:33:24 PM
Mine is here, and so is my Ninja tank. But I can't touch them 'til Christmas!  :-[

That's ok, I'll just shoot and tinker with my other airguns for now!  :D
Title: Re: QB79 Ninja - The $200 PCP
Post by: indianarifleman92 on December 14, 2015, 11:17:44 PM
 it's so bad I just put a qb79 .22 on pre order from airgun depot 8)
Title: Re: QB79 Ninja - The $200 PCP
Post by: WECSOG on December 27, 2015, 12:54:30 PM
Ok, I mounted the tank yesterday and have it shooting. I only put about 1800 psi in the tank to start with, in case it leaks or has some other problem that would necessitate a teardown. Actual pressure on the gun is the same regardless, but I didn't want to waste all that effort and then have to start over.
Took ~100 strokes of my Hill pump to reach the 1100 psi setpoint, then another 50 strokes got me to 1800.
 
Shot a few rounds into my indoor backstop. Shoots fine, but way to the right with factory sights. Doesn't seem to have leaked at all.

Today the plan is to work on the sights and bring it up to a full fill.
Title: Re: QB79 Ninja - The $200 PCP
Post by: wll2506 on January 02, 2016, 11:26:27 AM
I have two more .22 QB79's on order from AD.

After all my reading this little gun is a true firecracker. For me, mod1 and getting the velocity in the 740fps range with CPHP's is perfect for 30-35 yard starlings and the like, I would be very happy with that .

I have ordered some Discovery seals and ready to give it a go.

This is one of the very best postings on QB79 modifications that a lay person can understand that I have seen !

Great work Bob.

wll2506
Title: Re: QB79 Ninja - The $200 PCP
Post by: vigilandy on January 02, 2016, 12:31:49 PM
One of my favorite rifles is a 177 cal QB79 tuned by a forum member (nervoustrigger).  He set it up with a RVA,  cock on open, and lopped off a bit of the barrel to fix my accuracy problem.  Uses a standard 850 psi output Ninja tank to shoot  8.4gr pellets at 700fps.  Very pleasant to shoot,  and seems like it goes forever on a full tank.  Partial fills are great too and I use it to get the most out of my SCUBA tanks. 
Title: Re: QB79 Ninja - The $200 PCP
Post by: wll2506 on January 02, 2016, 01:16:43 PM
I just bought a AR2079 in .177 that I'm going to set up for accuracy, I have the 4x15x40mm Bushnell Trophy scope with AO already and have the mounts and rings. I will put a Umarex moderator on it to keep the noise down.

Don't think I'll do much playing with the velocity as I'm sure it shoots in the 750-800fps with 8 gr pellets ... way more than enough for my use, I want minute of fly accuracy at 15-20 yds ;-  ) I may try to de-tune it if the shot count and accuracy is not what I think it should be.

Wish the gun was here already !

wll
Title: Re: QB79 Ninja - The $200 PCP
Post by: Tater on January 02, 2016, 03:12:37 PM
One of my favorite rifles is a 177 cal QB79 tuned by a forum member (nervoustrigger).  He set it up with a RVA,  cock on open, and lopped off a bit of the barrel to fix my accuracy problem.  Uses a standard 850 psi output Ninja tank to shoot  8.4gr pellets at 700fps.  Very pleasant to shoot,  and seems like it goes forever on a full tank.  Partial fills are great too and I use it to get the most out of my SCUBA tanks. 

I bet that is a sweet shooter. He knows his stuff.
Title: Re: QB79 Ninja - The $200 PCP
Post by: nervoustrigger on January 02, 2016, 04:21:28 PM
Thanks Andy.  Thanks Jerry.  Just standing on the shoulders of giants  ;)
Title: Re: QB79 Ninja - The $200 PCP
Post by: wll2506 on January 03, 2016, 07:06:23 AM
One of my favorite rifles is a 177 cal QB79 tuned by a forum member (nervoustrigger).  He set it up with a RVA,  cock on open, and lopped off a bit of the barrel to fix my accuracy problem.  Uses a standard 850 psi output Ninja tank to shoot  8.4gr pellets at 700fps.  Very pleasant to shoot,  and seems like it goes forever on a full tank.  Partial fills are great too and I use it to get the most out of my SCUBA tanks.

Yes I have seen his post and he really knows his stuff.

For me and my skill level many of the things the guys do is is beyond me, so I just sit back and marvel at what they can do.

My demands are not as great as many here and a 700+ish fps QB79 shooting CPHP's is pretty easily done without going crazy. Changing out the breech seal to a Disco, a new Venturi bolt, and opening up of the barrel port should be easy enough to give me the zip I want. If I decide to get more power hungry, I would change the valve.

wll
Title: Re: QB79 Ninja - The $200 PCP
Post by: Tater on January 05, 2016, 01:48:37 AM


Yes I have seen his post and he really knows his stuff.

For me and my skill level many of the things the guys do is is beyond me, so I just sit back and marvel at what they can do.

My demands are not as great as many here and a 700+ish fps QB79 shooting CPHP's is pretty easily done without going crazy. Changing out the breech seal to a Disco, a new Venturi bolt, and opening up of the barrel port should be easy enough to give me the zip I want. If I decide to get more power hungry, I would change the valve.

wll

Same here wll.
Title: Re: QB79 Ninja - The $200 PCP
Post by: Michael Loar on January 05, 2016, 03:25:58 AM
I want one as well and already have the regulator so one question does the Pro SHP regulator thread into the QB tube or does it have a adapter block to attach regulator to QB tube and is that block part of the QB 79 package so all I would need is the gun and tank.

Mike
Title: Re: QB79 Ninja - The $200 PCP
Post by: nervoustrigger on January 05, 2016, 03:37:42 AM
Right, the QB79 has a tank block that accepts the Ninja regulator directly so all you need are the two things you mentioned.

For a QB78, you have to get a tank block and modify the air tube to accept it.
Title: Re: QB79 Ninja - The $200 PCP
Post by: Michael Loar on January 05, 2016, 04:03:40 AM
Ok so the base model QB 79 without the tank for 105.95 on AGD and a 13CI tank is all it takes to be shooting since I have the regulator.

mike
Title: Re: QB79 Ninja - The $200 PCP
Post by: WECSOG on January 07, 2016, 11:13:48 AM
Ok so the base model QB 79 without the tank for 105.95 on AGD and a 13CI tank is all it takes to be shooting since I have the regulator.

mike

Correct.
Title: Re: QB79 Ninja - The $200 PCP
Post by: Michael Loar on January 07, 2016, 12:35:03 PM
Cool, now the problem is no one sell just the tank without the regulator as its a ninja policy or DOT that a tank cannot be sold without a regulator so if anyone knows where just a tank can be bought  or has just a tank they would part with send me a PM as I am in need of just the tank since I have the regulator already so a tank and gun and I am on my way.

BD
Title: Re: QB79 Ninja - The $200 PCP
Post by: rsterne on January 07, 2016, 12:42:31 PM
RAP4 Paintball.... http://www.rap4.com/p/019690/13ci-compressed-air-tank-cylinder-no-regulator- (http://www.rap4.com/p/019690/13ci-compressed-air-tank-cylinder-no-regulator-)

Bob
Title: Re: QB79 Ninja - The $200 PCP
Post by: Michael Loar on January 07, 2016, 10:59:06 PM
RAP4 Paintball.... http://www.rap4.com/p/019690/13ci-compressed-air-tank-cylinder-no-regulator- (http://www.rap4.com/p/019690/13ci-compressed-air-tank-cylinder-no-regulator-)

Bob

Thanks Bob just what the doctor ordered.

Mike
Title: Re: QB79 Ninja - The $200 PCP
Post by: WECSOG on February 06, 2016, 07:15:35 PM
So here's an update on my QB Ninja. I hadn't touched it in awhile because it was deer season, wx was too bad for testing, etc. I need to pull the front end down, and wanted to chrono test it (on video) in its unmodified condition before I do that.

So today I pumped it back up (it leaks down in a couple days) to 2300 psi and chrono tested it. 580 fps avg w/CPHP 14.3 grain. Then I plinked. And plinked. And plinked. I plinked for about an hour and a half and nearly depleted the half-full 500 tin I started with. I shot at least 150 rounds. Yes, it fell out of regulation but was still holding close to the same point POI. And that is starting from only 2300 psi!

It still shoots a couple inches right at 25 yards, even after I've worked on bending the barrel. But I plan to put a scope on it and probably remove the irons, so I think the scope will have ample adjustment range to compensate.

I really want to keep a high shot count. My intentions are to remove the filter, unshroud the valve inlet, and fix the leak (probably tube to tank block); and nothing else. This is to be the gun that I pump to 3K, take it and a 500 tin of CPHP to informal airgunner meets, and shoot all day. :D
Title: Re: QB79 Ninja - The $200 PCP
Post by: wll2506 on February 07, 2016, 06:09:21 PM
So here's an update on my QB Ninja. I hadn't touched it in awhile because it was deer season, wx was too bad for testing, etc. I need to pull the front end down, and wanted to chrono test it (on video) in its unmodified condition before I do that.

So today I pumped it back up (it leaks down in a couple days) to 2300 psi and chrono tested it. 580 fps avg w/CPHP 14.3 grain. Then I plinked. And plinked. And plinked. I plinked for about an hour and a half and nearly depleted the half-full 500 tin I started with. I shot at least 150 rounds. Yes, it fell out of regulation but was still holding close to the same point POI. And that is starting from only 2300 psi!

It still shoots a couple inches right at 25 yards, even after I've worked on bending the barrel. But I plan to put a scope on it and probably remove the irons, so I think the scope will have ample adjustment range to compensate.

I really want to keep a high shot count. My intentions are to remove the filter, unshroud the valve inlet, and fix the leak (probably tube to tank block); and nothing else. This is to be the gun that I pump to 3K, take it and a 500 tin of CPHP to informal airgunner meets, and shoot all day. :D

You will be able to do it, my adventure with my "Woods Gun" has almost ended ... I will bump the regulator up to about 1250psi, remove the co2 piercing pin and that should give me ~850 fps with 10.5gr Kodiaks, I'm getting 810 now with a 1100 psi tank.

I have learned so much from these PCP forums my head is busting open ... I have also learned that "DOING IT" is much easier then reading about it .... one you see how things work, it is a piece of cake....(unless you have the leak from Heck, like I did)

My QB's/AR's are zipping along pretty good and I'm happy. My one QB79 in .22 that I got from AA I have not worked on yet. I will take a look at the valve and see if it has toys inside that are useless for a HPA application and go from there. Depending on the air port in the barrel may open that up to .150-.160. I will also drill the bottom out for better air flow. NOT as much as the other guys have done as right now I'm playing a bit on the conservative side. I'm looking for 800 ish fps with 14.3 CP's with this gun (Bolt is a pin type, so no modification is needed there).

EDIT ;

Well I opened the barrel port hole to .156 (9/32) and opened the back of the valve to a "Q" drill today. Removed the felt ring in the valve housing, and the co2 piercing pin. This should help. ran out of air in my filling tank so it looks like I'll be going the Sports Chalet tomorrow.

wll
Title: Re: QB79 Ninja - The $200 PCP
Post by: WECSOG on February 11, 2016, 08:57:10 PM
Today I took the front section off the valve, threw all the pieces parts I found within (except the poppet, of course) into the junk bin, and cut the front off. Threaded the remaining ring back on the valve and cut down a likely looking spring from my bucket o' springs to push apart the poppet and tank block. Smeared some Permatex blue RTV (sensor safe!) on the block sealing surface and slapped it back together.

Manana, to re-pressurize and test it.
Title: Re: QB79 Ninja - The $200 PCP
Post by: BigTinBoat on February 11, 2016, 10:40:19 PM
Today I took the front section off the valve, threw all the pieces parts I found within (except the poppet, of course) into the junk bin, and cut the front off. Threaded the remaining ring back on the valve and cut down a likely looking spring from my bucket o' springs to push apart the poppet and tank block. Smeared some Permatex blue RTV (sensor safe!) on the block sealing surface and slapped it back together.

Manana, to re-pressurize and test it.

Wondering why did you put this on?
Title: Re: QB79 Ninja - The $200 PCP
Post by: WECSOG on February 11, 2016, 10:52:16 PM
Because it was leaking before. At least, I think that's where the leak was.
Title: Re: QB79 Ninja - The $200 PCP
Post by: BigTinBoat on February 12, 2016, 12:26:04 AM
Because it was leaking before. At least, I think that's where the leak was.

Fairly certain that Permatex blue RTV will not withstand your regulated pressure. I think it is rated around 240psi. If it was leaking there before, it will still be leaking there.
That seal should require nothing more than a single o-ring to seal.
Title: Re: QB79 Ninja - The $200 PCP
Post by: Michael Loar on February 12, 2016, 02:33:38 AM
Because it was leaking before. At least, I think that's where the leak was.

Fairly certain that Permatex blue RTV will not withstand your regulated pressure. I think it is rated around 240psi. If it was leaking there before, it will still be leaking there.
That seal should require nothing more than a single o-ring to seal.

+1 on the permatex blue not holding up to HPA pressures and just the proper o ring is all that is required.

Mike
Title: Re: QB79 Ninja - The $200 PCP
Post by: WECSOG on February 12, 2016, 11:11:19 AM
I guess I'll find out, one way or the other. One member (pretty sure it was Ribbonstone) mentioned the block as the most likely point to leak, and advised painting the area with varnish. I'm pretty sure varnish isn't rated for 1100 psi either. Anyway, it was leaking down within a couple of days and the blue RTV is what I had, so I used it. If it fails, I'll try something else. :)
Title: Re: QB79 Ninja - The $200 PCP
Post by: nervoustrigger on February 12, 2016, 11:23:03 AM
I think the varnish is used differently.  It is not in the extrusion gap.  It fills in any potential scratches in the O-ring groove.  The varnish also pools in the corners to cradle the O-ring and puts it into a little better contact with the tube wall.

In any case, I hope you get the leak sorted.  Losing air is aggravating.
Title: Re: QB79 Ninja - The $200 PCP
Post by: Joe Brancato on February 12, 2016, 11:27:36 AM
Here are the results....

(http://i378.photobucket.com/albums/oo221/rsterne/QB%20on%20HPA/QBNinjaStage1_zpsd5b28c54.jpg) (http://s378.photobucket.com/user/rsterne/media/QB%20on%20HPA/QBNinjaStage1_zpsd5b28c54.jpg.html)

The average velocity while on reg. jumped up to 738 fps (17.3 FPE), giving 48 shots starting at 2000 psi before the velocity dropped below 730, and a total of 58 shooting down to 1000 psi.... That works out to 17 psi per shot, and an efficiency of 1.10 FPE/CI.... Starting from 3000 psi, you should get 105 shots down to just under 1200 psi.... This mild mannered gun is beginning to show some real promise.... The Stage 1 mods to accomplish it can all be done with a set of numbered drills and a needle file, plus a rubber seal.... and without removing the valve from the gun....

For the next round, however, I will be pulling the valve out to improve the airflow into the valve, and provide more volume between the regulator and the valve to increase the average pressure available during the shot cycle.... I'm really looking forward to seeing the results....

Bob

Bob, Could you make this shoot in the high 800s?  Forgive me if you (or someone else) has already stated they have done so in the 11 pages prior to my posting this question).

If you are interested in getting one to shoot in the high 800's, I have a number of 360 CC (22 Cu In) tanks, and I'd like to send one to you at no charge.  I'll even pay the shipping. I'd like to see what can be squeezed out of that rifle.

These measure 11.38" (about 4" longer than the 13 Cu In in you initial post). If they fit, I don't mind sending one to you. Heck, I'd even buy the gun if you decide to sell it.

You can post here (not sure if I'll see it, but will look),  pm, or call me at 714-612-5956
Title: Re: QB79 Ninja - The $200 PCP
Post by: WECSOG on February 12, 2016, 11:40:21 AM
I think the varnish is used differently.  It is not in the extrusion gap.  It fills in any potential scratches in the O-ring groove.  The varnish also pools in the corners to cradle the O-ring and puts it into a little better contact with the tube wall.

In any case, I hope you get the leak sorted.  Losing air is aggravating.

I still used the orings, btw. I just used the RTV as a dressing.
Title: Re: QB79 Ninja - The $200 PCP
Post by: nervoustrigger on February 12, 2016, 11:57:17 AM
Joe, a number of us have QB79 conversions pushing 30+ fpe which is in the velocity range you gave (say, 865fps with JSB 18.1gr heavies or well into the 900's with medium weights).  With the longer tube on the QB78, I've had them over 40fpe on HPA at 1500psi.

Not only are they powerful but extremely accurate with great triggers.

One of my writeups is in my signature if you are interested.  And if you're feeling philanthropic, I'd love to try one of your tanks.  In fact I have a lonely regulator that will need a home.  No worries if you don't, I respect that was an offer to Bob. 
Title: Re: QB79 Ninja - The $200 PCP
Post by: BigTinBoat on February 12, 2016, 12:19:03 PM

Bob, Could you make this shoot in the high 800s?  Forgive me if you (or someone else) has already stated they have done so in the 11 pages prior to my posting this question).

Like Jason said - easy to do. Heck my reverse bottled (with a 13ci) QB78 is getting 845fps in .25 (JSB kings 25.4) for 40FPE.

My 79 on 1500psi would get 23FPE in .177 so that would equate to 850FPS using 14.3 pellets, and the .22 should be more efficient
Title: Re: QB79 Ninja - The $200 PCP
Post by: wll2506 on February 12, 2016, 04:09:29 PM

Bob, Could you make this shoot in the high 800s?  Forgive me if you (or someone else) has already stated they have done so in the 11 pages prior to my posting this question).

Like Jason said - easy to do. Heck my reverse bottled (with a 13ci) QB78 is getting 845fps in .25 (JSB kings 25.4) for 40FPE.

My 79 on 1500psi would get 23FPE in .177 so that would equate to 850FPS using 14.3 pellets, and the .22 should be more efficient

I put on a 22ci tank and put in a .010 shim today in the regulator - will test it out today when I get home. Here is a pic.

wll

Edit:

That combo gave me 885fps with 10.5 Kodiaks.... I'm very, very pleased. The outgoing is just under 1300 psi. The 22 ci tank works out great ! I may get a couple more 22 ci tanks, they work for my application.

This gun now is a monster !

wll
Title: Re: QB79 Ninja - The $200 PCP
Post by: Michael Loar on February 12, 2016, 05:33:43 PM
Here are the results....

(http://i378.photobucket.com/albums/oo221/rsterne/QB%20on%20HPA/QBNinjaStage1_zpsd5b28c54.jpg) (http://s378.photobucket.com/user/rsterne/media/QB%20on%20HPA/QBNinjaStage1_zpsd5b28c54.jpg.html)

The average velocity while on reg. jumped up to 738 fps (17.3 FPE), giving 48 shots starting at 2000 psi before the velocity dropped below 730, and a total of 58 shooting down to 1000 psi.... That works out to 17 psi per shot, and an efficiency of 1.10 FPE/CI.... Starting from 3000 psi, you should get 105 shots down to just under 1200 psi.... This mild mannered gun is beginning to show some real promise.... The Stage 1 mods to accomplish it can all be done with a set of numbered drills and a needle file, plus a rubber seal.... and without removing the valve from the gun....

For the next round, however, I will be pulling the valve out to improve the airflow into the valve, and provide more volume between the regulator and the valve to increase the average pressure available during the shot cycle.... I'm really looking forward to seeing the results....

Bob

Bob, Could you make this shoot in the high 800s?  Forgive me if you (or someone else) has already stated they have done so in the 11 pages prior to my posting this question).

If you are interested in getting one to shoot in the high 800's, I have a number of 360 CC (22 Cu In) tanks, and I'd like to send one to you at no charge.  I'll even pay the shipping. I'd like to see what can be squeezed out of that rifle.

These measure 11.38" (about 4" longer than the 13 Cu In in you initial post). If they fit, I don't mind sending one to you. Heck, I'd even buy the gun if you decide to sell it.

You can post here (not sure if I'll see it, but will look),  pm, or call me at 714-612-5956

Joe

How much for just a tank with no regulator and are they 2 inches in OD just longer than the 13ci tanks.

Mike
Title: Re: QB79 Ninja - The $200 PCP
Post by: rsterne on February 13, 2016, 12:24:07 AM
Joe, you didn't read quite far enough in this thread.... back on page 4, post #76 is what you are looking for....  http://www.gatewaytoairguns.org/GTA/index.php?topic=49943.60 (http://www.gatewaytoairguns.org/GTA/index.php?topic=49943.60)

In fact, by adding the new SSG, I have gained even more shots.... This is on a 13CI tank, running at only 1200 psi....

(http://i378.photobucket.com/albums/oo221/rsterne/QB%20on%20HPA/QB%20Ninja%20with%20SSG_zpsnojreotf.jpg) (http://s378.photobucket.com/user/rsterne/media/QB%20on%20HPA/QB%20Ninja%20with%20SSG_zpsnojreotf.jpg.html)

By increasing the pressure to 1400 psi, you could push into the high 800s.... With a 22 CI tank you should be able to get over 100 shots at that power.... I don't tune guns or supply parts for anyone but myself, but all the information is here, right in this thread.... and it's not magic....

Bob

Title: Re: QB79 Ninja - The $200 PCP
Post by: Sfttailrdr46 on February 13, 2016, 09:01:56 AM
So here's an update on my QB Ninja. I hadn't touched it in awhile because it was deer season, wx was too bad for testing, etc. I need to pull the front end down, and wanted to chrono test it (on video) in its unmodified condition before I do that.

So today I pumped it back up (it leaks down in a couple days) to 2300 psi and chrono tested it. 580 fps avg w/CPHP 14.3 grain. Then I plinked. And plinked. And plinked. I plinked for about an hour and a half and nearly depleted the half-full 500 tin I started with. I shot at least 150 rounds. Yes, it fell out of regulation but was still holding close to the same point POI. And that is starting from only 2300 psi!

It still shoots a couple inches right at 25 yards, even after I've worked on bending the barrel. But I plan to put a scope on it and probably remove the irons, so I think the scope will have ample adjustment range to compensate.


I would be a little concerned with the horizontal error because your 25 yard zero will probably need more correction for 30, 40 and 50 yards if you shot at those distances. Vertical is not as problematic since hold over and under can pretty easily compensate with a mil dot scope. Correcting windage on the fly can be a little more challenging if you need to correct for the rifle and the breeze
Title: Re: QB79 Ninja - The $200 PCP
Post by: WECSOG on February 13, 2016, 10:19:08 AM
I'll probably try bending it a little more after all. I can't get the valve poppet to seal with my hand pump, so I'm gonna pull it all the way down again. So I guess I'll work on the barrel while it's out.

BTW, did I mention that the stock nut was stripped, out of the box? These things really are parts kits, in my experience. Don't get me wrong; I fully intend to make this a viable airgun, and am enjoying the process of doing so. But if I were like some of my fellow MPP consumers, I would have already written this thing off as a piece of junk and sent it back; and would now be telling everyone who would listen to save their money.  ;)

And I'm not referring to the poppet seal problem; that one was my doing by choosing the wrong spring.
Title: Re: QB79 Ninja - The $200 PCP
Post by: Michael Loar on February 14, 2016, 05:15:34 AM
Tracy
The easiest way I have found to bend a barrel straight is to optically center the scope you are going to use and mount it on the gun then at what ever distance you shoot at most take three shots to see where the pellet hits. Then using a 1/2" ID PVC piece of pipe about 6 inches long clamped in a 4 or 6 inch jawed vice so that the barrel with out front sight or brake will fit in it about the 6 inches of PVC pipe and bend the barrel by applying pressure to action and stock in the direction the pellets needs to go. then shoot again at the same distance and repeat until your POI and POA are within 1 inch of each other and you will be good to sight in final amount with turret adjustments and be very close to center in the scope.

I have used this method many times with good success. It takes the guess work out of it just bend slow and shoot a lot.

Mike 
Title: Re: QB79 Ninja - The $200 PCP
Post by: WECSOG on February 14, 2016, 11:34:57 AM
Thanks, Mike. That sounds like a good plan of action.
Title: Re: QB79 Ninja - The $200 PCP
Post by: pllagunos on February 14, 2016, 01:56:30 PM
I finally finished to mod my qb79 .177, my results are 690fps with the 10,5 CPUMs using the stock (850 psi) regulator  ;D I actually wanted 12 fpe, but I am not going to complain since I haven't done any valve mods yet, and also I think my breach seal isn't set perfectly. What I did is removed the piercing pin and filter from the valve, enlarged the ports  to 9/64" along with the poly tubing seal, which was a pain to cut, also installed a RVA and the cock on open mod; I polished everything to a smooth finish and finally lubed with moly paste and silicone grease.

I can tell you guys, that it is a sweat shooter, it's accurate and has enough energy to dispatch small game at close distances and it is VERY fun to shoot.
Title: Re: QB79 Ninja - The $200 PCP
Post by: SpiralGroove on February 14, 2016, 03:33:15 PM
Hey Pablo,
How many shots do you get per 213cc tank full?
Have you increased the bolt probe tip to 9/64"?
Are you getting 690 fps on the knee of the curve or at max. preload?

You only need another 25/30 fps to reach your goal of 12 fpe :D  The easiest thing to do would be to increase your set-point a tad - maybe 900/950 psi.
Title: Re: QB79 Ninja - The $200 PCP
Post by: pllagunos on February 14, 2016, 04:46:30 PM
Hey Pablo,
How many shots do you get per 213cc tank full?
Have you increased the bolt probe tip to 9/64"?
Are you getting 690 fps on the knee of the curve or at max. preload?

You only need another 25/30 fps to reach your goal of 12 fpe :D  The easiest thing to do would be to increase your set-point a tad - maybe 900/950 psi.
Hey Kirk,
I am not sure how many shots per fill I get, I am going to make a full chorine one of these days, however I do know that it gives me a lot! I actually filled to 2100psi and the needle hasn't moved much even after 20shots for me it looks like the needle is at 1900psi however I will continue shooting and once I get to 1500psi I can get an estimate of my efficiency.

Yes I increased the bolt probe to 9/64", I am getting between 680-694fps, 685fps avg I would think... I am not sure if it's on the knee of the curve but it is close, definitely not at max preload, I tried to set the RVA where I can hear the valve opening in a more consistent way, kind of a quick snap.

I will try to increase the set point, however I don't have an output pressure device so that would be a main problem.
Title: Re: QB79 Ninja - The $200 PCP- adjusting regulators
Post by: mackeral5 on February 14, 2016, 05:15:38 PM
here is a good thread discussing regulator adjustment. 


http://www.gatewaytoairguns.org/GTA/index.php?topic=49648.20 (http://www.gatewaytoairguns.org/GTA/index.php?topic=49648.20)
Title: Re: QB79 Ninja - The $200 PCP
Post by: Kailua on February 14, 2016, 05:49:56 PM
I'll probably try bending it a little more after all. I can't get the valve poppet to seal with my hand pump, so I'm gonna pull it all the way down again. So I guess I'll work on the barrel while it's out.

BTW, did I mention that the stock nut was stripped, out of the box? These things really are parts kits, in my experience. Don't get me wrong; I fully intend to make this a viable airgun, and am enjoying the process of doing so. But if I were like some of my fellow MPP consumers, I would have already written this thing off as a piece of junk and sent it back; and would now be telling everyone who would listen to save their money.  ;)

And I'm not referring to the poppet seal problem; that one was my doing by choosing the wrong spring.

I had read a while back on the Flying Dragon website that the newer QBs are not as well make as the older guns. As you have mentioned these are project guns which can be fixed to perform better.
Title: Re: QB79 Ninja - The $200 PCP
Post by: SpiralGroove on February 15, 2016, 12:59:37 AM
Hey Pablo,
If you pay to ship the Ninja regulator to me I can set it wherever you want.
Kirk
Title: Re: QB79 Ninja - The $200 PCP
Post by: Michael Loar on February 15, 2016, 01:11:10 AM
Thanks, Mike. That sounds like a good plan of action.

Tracy

Not a problem and its frustrating to have a gun that shoot way off its mark so that a scope runs out of adjustment before getting close to the bulls. Like I said just go slow and shoot after every adjustment so you can see the change in POIs.

Mike
Title: Re: QB79 Ninja - The $200 PCP
Post by: jpsgunworks on February 17, 2016, 11:58:13 AM
Does the tank with the pro SHP regulator just screw on or does the barrel have to be pulled ? With a regular Ninja
tank and regulator the gauge and fill nipple don't clear without taking the barrel off.  I want to carry extra tanks and
change them like you would a CO2 tank. Thanks.
Title: Re: QB79 Ninja - The $200 PCP
Post by: BigTinBoat on February 17, 2016, 12:27:58 PM
Does the tank with the pro SHP regulator just screw on or does the barrel have to be pulled ? With a regular Ninja
tank and regulator the gauge and fill nipple don't clear without taking the barrel off.  I want to carry extra tanks and
change them like you would a CO2 tank. Thanks.

Won't work without a breech riser
Title: Re: QB79 Ninja - The $200 PCP
Post by: rsterne on February 17, 2016, 01:12:28 PM
Unscrewing an HPA tank that still has 1000 psi or more in it will likely blow the O-ring on the ASA fitting.... Even though the QB tank block has a small vent hole to prevent this from being dangerous (not sure if the JDS one does?).... they are only designed to be unscrewed when a CO2 tank is empty and the pressure is very low.... You can fit an On-Off valve between the regulator and tank block which will then allow you to remove the tank (after firing the gun to depressurize the tank block).... but as the previous poster mentioned, you will need either a riser breech, or an offset (lower) block adapter.... to be able to unscrew the tank with the barrel in place.... Most guys just use a Pony Tank to top up the bottle on the gun....

Bob
Title: Re: QB79 Ninja - The $200 PCP
Post by: BigTinBoat on February 17, 2016, 04:27:58 PM
Unscrewing an HPA tank that still has 1000 psi or more in it will likely blow the O-ring on the ASA fitting....

When I unscrew mine with 1500psi of regulated pressure I just unscrew the bottle 1 complete turn. I then dry fire a couple of times and the bottle easily unscrews without any pressure on it at all.
Title: Re: QB79 Ninja - The $200 PCP
Post by: bugg100 on February 17, 2016, 05:13:30 PM
I am thinking of trying a 79 out with the Ninja SHP, lots of great info here, thanks to all for sharing!

I haven't seen it referenced in this thread directly... So does the Ninja tank fit without interference of the barrel, or is an aftermarket tank block required? Not asking about removing the bottle, just curious about shooting conditions.

thanks in advance,
Joe
Title: Re: QB79 Ninja - The $200 PCP
Post by: BigTinBoat on February 17, 2016, 07:07:55 PM
I am thinking of trying a 79 out with the Ninja SHP, lots of great info here, thanks to all for sharing!

I haven't seen it referenced in this thread directly... So does the Ninja tank fit without interference of the barrel, or is an aftermarket tank block required? Not asking about removing the bottle, just curious about shooting conditions.

thanks in advance,
Joe


Yes - the Ninja tank will screw on to the tank block w/i touching the barrel after installation.
Title: Re: QB79 Ninja - The $200 PCP
Post by: birdmove on February 17, 2016, 09:38:12 PM
    Sorry, as I haven't read through this whole thread yet. The tank the original poster suggests, are they fillable with a hand pump, such as used on Crosman Discovery airguns?

    Thanks, Jon
Title: Re: QB79 Ninja - The $200 PCP
Post by: Michael Loar on February 17, 2016, 11:51:51 PM
RAP4 Paintball.... http://www.rap4.com/p/019690/13ci-compressed-air-tank-cylinder-no-regulator- (http://www.rap4.com/p/019690/13ci-compressed-air-tank-cylinder-no-regulator-)

Bob

Bob
I checked out the tank link you sent me again and the price is good till you get to the shipping which is 17 bucks so that it puts just the tank 3 bucks shy of a complete ninja tank and regulator off eBay with free shipping so likely will just go that route and resell the regulator that comes with the tank since my SHP is already set to 1100 psi output. I have one other question concerning velocity.

I am wanting the gun for FT use so am looking to shoot JSB 177 cal 10.34 grain pellets at 890 to 900 fps and am trying to decide on if I need the extra plenum volume of a QB78 as compared to the 79s plenum to achieve the fps I am after from the gun or would the smaller 79s plenum be enough to achieve my intended fps with just the bolt and valve mods of opening up the transfer port and removing the front of the valve nose or reducing its unneeded material.

I am really liking the AR2079 target gun for the stock but don't want to get it and have to do extensive mods to get the 890 to 900 fps with 10.34 JSBs. The AR 2078 thumbhole is also being considered  so just asking which you think would be the best candidate for my plans. I know the 2078 would need the tank block added so that's also another factor as far as additional work to covert to HPA as compared to the 2079 or QB79.

Your thoughts.

Mike
Title: Re: QB79 Ninja - The $200 PCP
Post by: mackeral5 on February 18, 2016, 06:47:17 AM

Make sure the 2079 is actually available before you get your hopes up.  I don't believe any loose guns are available, only packages with scopes, tanks, etc.  Add to cart and you will see if there are any in stock.  you will find that a lot of QB stuff listed on the Archer site are actually out of stock.
Title: Re: QB79 Ninja - The $200 PCP
Post by: Michael Loar on February 18, 2016, 08:37:21 AM
Mike
I will check it out and see as you may be right , thanks

Mike
Title: Re: QB79 Ninja - The $200 PCP
Post by: rsterne on February 18, 2016, 12:36:01 PM
I haven't built a '79 in .177, but if you max out the available plenum volume you should be OK.... You may need to run up to 1400 psi, but there is no reason you shouldn't be able to get 20 FPE.... but as I say I haven't built one....

Bob
Title: Re: QB79 Ninja - The $200 PCP
Post by: Michael Loar on February 18, 2016, 12:47:53 PM
Bob
Thanks as I was kind of thinking the same thing but just want your opinion and spiral groove has one for sale now that he says is making 19 fpe with CP 10.5s with your stage 1 and 2 mods so I believe it is possible.

ASlso found a good deal on a QB 78 NIB that I am going to get so its a non issue now anyway as I know the 78 will be more than capable of achieving it.

Thanks Mike
Title: Re: QB79 Ninja - The $200 PCP
Post by: wll2506 on February 18, 2016, 07:22:30 PM
I'll probably try bending it a little more after all. I can't get the valve poppet to seal with my hand pump, so I'm gonna pull it all the way down again. So I guess I'll work on the barrel while it's out.

BTW, did I mention that the stock nut was stripped, out of the box? These things really are parts kits, in my experience. Don't get me wrong; I fully intend to make this a viable airgun, and am enjoying the process of doing so. But if I were like some of my fellow MPP consumers, I would have already written this thing off as a piece of junk and sent it back; and would now be telling everyone who would listen to save their money.  ;)

And I'm not referring to the poppet seal problem; that one was my doing by choosing the wrong spring.

I had read a while back on the Flying Dragon website that the newer QBs are not as well make as the older guns. As you have mentioned these are project guns which can be fixed to perform better.

I had a couple of very old QB 78's many, many years ago, and through them out when I did not know any better.

As I remember they were not made as well as the guns that are coming through now, The guns now seem pretty nice, at least I think so ?

wll
Title: Re: QB79 Ninja - The $200 PCP
Post by: vigilandy on February 18, 2016, 08:17:51 PM
I picked up an older one recently.  Haven't shot it,  but the wood quality is definitely nicer on the new ones.  No more of that yellowish varnish!
Title: Re: QB79 Ninja - The $200 PCP
Post by: southern gun on February 18, 2016, 09:21:49 PM
I have ordered a QB78 and was wanting to know the best tank block to put on it
Thanks
Title: Re: QB79 Ninja - The $200 PCP
Post by: WECSOG on February 20, 2016, 02:02:14 PM
    Sorry, as I haven't read through this whole thread yet. The tank the original poster suggests, are they fillable with a hand pump, such as used on Crosman Discovery airguns?

    Thanks, Jon

Yes. I use a Hill pump to fill mine.
Title: Re: QB79 Ninja - The $200 PCP
Post by: Michael Loar on February 24, 2016, 09:44:32 AM
I have ordered a QB78 and was wanting to know the best tank block to put on it
Thanks

+2 on that as I have acquired a QB 78 as well and would like to know which tank block is best to use the older two o ring style or the new four o ring style or is there any real difference other than the extra o rings. Does one flow better than the other or anything else we should know so as to get the best one for the job at hand.

Mike
Title: Re: QB79 Ninja - The $200 PCP
Post by: nervoustrigger on February 24, 2016, 10:27:11 AM
No real advantage to the 2 vs 4 O-ring version.  The idea is more = better but reality is if there is a burr in the air tube, it will cut 4 o-rings instead of 2.  Deburring and using silicone grease for assembly are the keys to success.
Title: Re: QB79 Ninja - The $200 PCP
Post by: SpiralGroove on February 24, 2016, 01:19:17 PM
Hey Guys,
Most people will find it difficult to find a tank block for a QB78 HPA conversion -> Period :P
I bought two from Arrrcher Airguns last month, but he isn't listing them anymore?
The cheapest they can be found is $35+ shipping, JDS have them for $75+ (which I refuse to pay since the whole gun only cost $95).

Good Luck 8)
Title: Re: QB79 Ninja - The $200 PCP
Post by: Michael Loar on February 24, 2016, 01:48:22 PM
Hey Guys,
Most people will find it difficult to find a tank block for a QB78 HPA conversion -> Period :P
I bought two from Arrrcher Airguns last month, but he isn't listing them anymore?
The cheapest they can be found is $35+ shipping, JDS have them for $75+ (which I refuse to pay since the whole gun only cost $95).

Good Luck 8)

So the ones listed on the site for 35 bucks now are not suitable for HPA even when regulated to 1500 psi or less as they state not to exceed 1100 psi and not for HPA but regulated its really no more pressure than CO2 at 90 plus degree temps.

Any thoughts

Mike
Title: Re: QB79 Ninja - The $200 PCP
Post by: rsterne on February 24, 2016, 02:03:23 PM
I would think the warning is a just a CYA for the lawyers, because CO2 at 120*F reaches 1900 psi.... The biggest problem with the stock QB tank block is that the screws are soft, and too close to the end of the tube.... The JDS block moves them further from the end, and if you use high-tensile screws is a much safer arrangement.... One thing that concerns me slightly is when I see guys using the stock QB tank block in a QB78 (or Crosman) tube without inletting the stock for the block and using the two side stock screws as used in the QB79.... Since I am aware of one QB79 tank block that pulled out of the end of a tube (when not in a stock) by shearing the screws and nearly ripping the holes out, at only 2600 psi.... That tells you what the safety margin is at 1800 psi.... less than 1.5:1.... It must be a bit better with the stock screws in place, no?.... I would not recommend even removing a QB79 action from the stock while pressurized....

Bob
Title: Re: QB79 Ninja - The $200 PCP
Post by: Michael Loar on February 24, 2016, 02:33:15 PM
I would think the warning is a just a CYA for the lawyers, because CO2 at 120*F reaches 1900 psi.... The biggest problem with the stock QB tank block is that the screws are soft, and too close to the end of the tube.... The JDS block moves them further from the end, and if you use high-tensile screws is a much safer arrangement.... One thing that concerns me slightly is when I see guys using the stock QB tank block in a QB78 (or Crosman) tube without inletting the stock for the block and using the two side stock screws as used in the QB79.... Since I am aware of one QB79 tank block that pulled out of the end of a tube (when not in a stock) by shearing the screws and nearly ripping the holes out, at only 2600 psi.... That tells you what the safety margin is at 1800 psi.... less than 1.5:1.... It must be a bit better with the stock screws in place, no?.... I would not recommend even removing a QB79 action from the stock while pressurized....

Bob

Bob
Is it possible with the 2 o ring block to not only upgrade the screws to grade 8 screws but add two more screws between the 2 o rings in the block to have a total of 4 screws holding it in the guns tube and thereby increasing the safety factor close to the preferred 3:1 ratio. I don't have my QB 78 as of yet it will be here tomorrow so not exactly sure how the stock helps secure the block since I don't have a visual in front of me, but I was planning on modifying an extra FWB 300 target stock I have to accept the QB action and can inlet or modify the stock to add support for the screws as well if needed. I don't have a block either to visualize so just guessing at this point.

If just adding two more screws in between the 2 o rings on the block would be acceptable then that would be an easy modification and put me at ease with it being safe or if you think the JDS block is the way I should go then that is what I will go with so just asking your opinion on the correct safe way to proceed.

Mike
 
Title: Re: QB79 Ninja - The $200 PCP
Post by: SpiralGroove on February 24, 2016, 03:45:54 PM
Hey Mike,
They are still listed - just not with a picture ::)  They are now $36.99+ shipping.  He raised the price since I bought them.  These blocks are fine.  Just make sure the Block is well secured to the stock as well as the air cylinder or pinned if not attached to stock.

(http://i113.photobucket.com/albums/n227/kirk_schwarz/IMG_1541_zpshxfki4lw.jpg) (http://s113.photobucket.com/user/kirk_schwarz/media/IMG_1541_zpshxfki4lw.jpg.html)

Before, I only saw the Co2, thread on adapter for $31.99, which is Not for HPA.

 
Title: Re: QB79 Ninja - The $200 PCP
Post by: nervoustrigger on February 24, 2016, 04:21:18 PM
You can certainly do that.  Other approaches are to add one screw underneath or by adding a shear pin.  Any of these significantly improve the integrity.

The biggest risk in my opinion is not that the pressure is likely to blow the tank block off the end, rather it's what happens if the gun gets dropped or something slams into the bottle and puts a lot of torque and stress on it. 
Title: Re: QB79 Ninja - The $200 PCP
Post by: pllagunos on February 24, 2016, 04:42:55 PM
My qb79 is running a 850psi output regged bottle, I haven't changed the tank block screws to higher quality ones, is it really needed for such a low pressure?
Title: Re: QB79 Ninja - The $200 PCP
Post by: nervoustrigger on February 24, 2016, 04:45:47 PM
If your bottle is fitted with a 1.5k low side burst disk, not really but it's an easy thing to do for some peace of mind.
Title: Re: QB79 Ninja - The $200 PCP
Post by: SpiralGroove on February 24, 2016, 06:16:52 PM
Pablo,
If you've got kids around, every day accidents seem to be part of life.
The screws in question are about .35 to .50 cents each at the local hardware store, so well worth the time & $$ to replace.

I don't want to make an "accident video" to submit to the GTA :o  The guy who took the Disco valve in the thigh, easily could have died if a take #2 was produced.   

Title: Re: QB79 Ninja - The $200 PCP
Post by: Michael Loar on February 24, 2016, 06:39:52 PM
Hey Mike,
They are still listed - just not with a picture ::)  They are now $36.99+ shipping.  He raised the price since I bought them.  These blocks are fine.  Just make sure the Block is well secured to the stock as well as the air cylinder or pinned if not attached to stock.

(http://i113.photobucket.com/albums/n227/kirk_schwarz/IMG_1541_zpshxfki4lw.jpg) (http://s113.photobucket.com/user/kirk_schwarz/media/IMG_1541_zpshxfki4lw.jpg.html)

Before, I only saw the Co2, thread on adapter for $31.99, which is Not for HPA.

 

Kirk and all
Thanks as that's what I wanted to know and was going to grab one up before he runs out again and the one extra screw underneath sounds like the best route to go for ease of modifying.

I see he has the 2 and 4 o ring blocks priced the same so might as well get the extra sealing protection of 4 o rings.

Mike
Title: Re: QB79 Ninja - The $200 PCP
Post by: pllagunos on February 24, 2016, 06:45:43 PM
Pablo,
If you've got kids around, every day accidents seem to be part of life.
The screws in question are about .35 to .50 cents each at the local hardware store, so well worth the time & $$ to replace.

I don't want to make an "accident video" to submit to the GTA :o  The guy who took the Disco valve in the thigh, easily could have died if a take #2 was produced.
I will buy some, better safe than sorry, which size are they? Also are they the ones that secure the bock to the stock or the block to the tube?
Title: Re: QB79 Ninja - The $200 PCP
Post by: SpiralGroove on February 24, 2016, 07:24:02 PM
I believe they're both 4mm.
 - The air cylinder screws use an Allen Wrench.
- The Stock screws have a round head and take a Phillips driver.

I usually buy them longer than necessary, say 7mm/10mm in length, and grind down to fit.

Home Depot is your best bet 8)
Title: Re: QB79 Ninja - The $200 PCP
Post by: southern gun on February 24, 2016, 08:32:03 PM
Just so I'm clear we are talking about grade 8 bolts correct? My QB 78 came yesterday so I'm ready to get this started.
Title: Re: QB79 Ninja - The $200 PCP
Post by: rsterne on February 24, 2016, 08:45:11 PM
I used a 3/16" shear pin when installing a QB block into a tube where the block is not also bolted into the stock....

(http://i378.photobucket.com/albums/oo221/rsterne/22%20PCP/QB3.jpg) (http://s378.photobucket.com/user/rsterne/media/22%20PCP/QB3.jpg.html)

I even added one more 8-32 screw in the top as well, with the head set into a pocket in the block.... It is cut the right length to touch the through-pin (which has a flat) to hold it in place.... Overkill, but the stock screws were so close to the end they scared me.... With this installation they could be left out, in fact the tube would be stronger without drilling holes for them....

Bob
Title: Re: QB79 Ninja - The $200 PCP
Post by: Michael Loar on February 24, 2016, 08:56:44 PM
Bob
Very clean and secure for sure and only one set of extra threads to cut, I like it.

Always good designs for sure.

Mike
Title: Re: QB79 Ninja - The $200 PCP
Post by: Bryan Heimann on February 24, 2016, 09:08:25 PM
Thank you
Title: Re: QB79 Ninja - The $200 PCP
Post by: wll2506 on February 24, 2016, 09:14:09 PM
I would think the warning is a just a CYA for the lawyers, because CO2 at 120*F reaches 1900 psi.... The biggest problem with the stock QB tank block is that the screws are soft, and too close to the end of the tube.... The JDS block moves them further from the end, and if you use high-tensile screws is a much safer arrangement.... One thing that concerns me slightly is when I see guys using the stock QB tank block in a QB78 (or Crosman) tube without inletting the stock for the block and using the two side stock screws as used in the QB79.... Since I am aware of one QB79 tank block that pulled out of the end of a tube (when not in a stock) by shearing the screws and nearly ripping the holes out, at only 2600 psi.... That tells you what the safety margin is at 1800 psi.... less than 1.5:1.... It must be a bit better with the stock screws in place, no?.... I would not recommend even removing a QB79 action from the stock while pressurized....

Bob

Bob,

That is exactly why I bought some high strength alloy screws and will install the as soon as my pressure in this tank runs out...I bought 4x .7 x 10mm long screws, they may be a little long but I can grind them down !

wll
Title: Re: QB79 Ninja - The $200 PCP
Post by: Michael Loar on February 24, 2016, 11:47:13 PM
Can anyone tell me if the barrel on the QBs and the FDAR PCP 60C are the same and interchangeable between the two guns.

I have a LW 177 cal barrel for a 60C that if my new QB is not a shooter I would like to know if they could be swapped without modifications.

Mike
Title: Re: QB79 Ninja - The $200 PCP
Post by: nervoustrigger on February 24, 2016, 11:58:21 PM
I can't answer your question in a detailed manner but I took this picture for some guys in chat a few months ago:

(http://i779.photobucket.com/albums/yy80/jmneal1/temp/QB%20and%20FD%20PCP%20barrels_zpsjyx0zk0s.jpg)
Title: Re: QB79 Ninja - The $200 PCP
Post by: Michael Loar on February 25, 2016, 12:06:59 AM
I can't answer your question in a detailed manner but I took this picture for some guys in chat a few months ago:

(http://i779.photobucket.com/albums/yy80/jmneal1/temp/QB%20and%20FD%20PCP%20barrels_zpsjyx0zk0s.jpg)

Jason
Its a Gen 1 barrel so from the pic it looks promising as a drop in swap as the loading shelf may be a bit short but I can make a tray to take up the space.

Thanks Mike
Title: Re: QB79 Ninja - The $200 PCP
Post by: rsterne on February 25, 2016, 01:26:45 AM
You probably don't need to extend the loading tray.... the bolt probe probably covers the gap at the back....

Bob
Title: Re: QB79 Ninja - The $200 PCP
Post by: Michael Loar on February 25, 2016, 01:46:08 AM
Bob
I will know soon enough since my QB will be here tomorrow. But I am going to enjoy it some with CO2 first and then install my 60C fill fitting and try it on 1500 psi HPA before I start my conversion to the bottled HPA FT gun.

Mike
Title: Re: QB79 Ninja - The $200 PCP
Post by: pllagunos on February 25, 2016, 10:59:18 PM
I believe they're both 4mm.
 - The air cylinder screws use an Allen Wrench.
- The Stock screws have a round head and take a Phillips driver.

I usually buy them longer than necessary, say 7mm/10mm in length, and grind down to fit.

Home Depot is your best bet 8)
That's weird, mine has standard phillips screws.

So, they are 4mm x 10mm and replace the stock screws?

Thanks
Title: Re: QB79 Ninja - The $200 PCP
Post by: nervoustrigger on February 25, 2016, 11:22:40 PM
From the factory, I'm accustomed to seeing Phillips heads on both sets of screws going into the tank block.

Both are M4-0.7 as previously stated.

8mm length works great for the ones passing through the air tube.

10-12mm length is good for the ones passing through the stock.
Title: Re: QB79 Ninja - The $200 PCP
Post by: Michael Loar on February 26, 2016, 12:39:29 AM
I am thinking of going to 8-32 or 10-32 allen screws countersunk like the Prod and Mrods use to greatly increase the loaded area of the screws with either three screws or 4 screws with two on either side in front and between the o rings on a 2 o ring block or like Bob did with the cross pin and top screw to secure the pin.

Way over kill I know but I like to feel safe while shooting also.

Mike

Title: Re: QB79 Ninja - The $200 PCP
Post by: soarwitheagles on February 27, 2016, 01:16:11 PM
Awesome thread here.  Thanks for all the info.

I read through most of these posts, but still am not sure if I can do the mods myself.

Will I need any machine shop tools to accomplish these mods?

Also, can someone tell me the exact items I would need to purchase  and where to purchase them to complete the mod safely?

Thank you,

Soar

PS We have tons of Big 5's near us.  So I am keeping my eyes peeled for a good deal!
Title: Re: QB79 Ninja - The $200 PCP
Post by: Michael Loar on February 27, 2016, 02:20:06 PM
Soar
If you read this thread closely all the info you just asked about is in it and no you don't really need machine shop tools to do these mods but they do make it easier. I have only a drill press and dremel at home but do have access to a buddies machine shop at his house.

Got my new QB 78 Thursday and have been playing with it some in stock form and so far on a 50 degree day with the 2 CO2 powerlets it shoots JSB 10.34s at 600 fps and 8.44s at 625 fps for a total of 85 shots. I have removed the open sights and added a LDC and polished the trigger sear contact points and adjusted it for a nice light and crisp release and installed a 3x7x32 hawke AO scope on it for some grouping tests to see if it needs the LW target barrel put in it when I start my mods. I have the tank block and bottle on its way so after some further testing the conversion to HPA will begin. 

I am going to shoot it some with my 60C fill fitting in place of the CO2 cap so I can see just what it does at different pressures of HPA to get a better idea of just how far I need to go to achieve my goal of 900 fps with JSB 10.34s for FT matches in the hunter class.

Mike
Title: Re: QB79 Ninja - The $200 PCP
Post by: Michael Loar on February 27, 2016, 02:23:41 PM
You probably don't need to extend the loading tray.... the bolt probe probably covers the gap at the back....

Bob

Bob

With gun in hand I believe you are correct in that the probe will cover the space behind the loading tray without issue with the LW barrel.

Mike
Title: Re: QB79 Ninja - The $200 PCP
Post by: SpiralGroove on February 27, 2016, 04:28:21 PM
Hey Mike,
Keep us posted on your progress :D.
If you get a normal QB barrel, you shouldn't need the LW replacement.
However, for use in FT, maybe it would give you a little more accuracy.  Unfortunately, the LW barrel likely costs almost as much as the QB itself ???
Title: Re: QB79 Ninja - The $200 PCP
Post by: Michael Loar on February 27, 2016, 10:30:37 PM
Hey Mike,
Keep us posted on your progress :D.
If you get a normal QB barrel, you shouldn't need the LW replacement.
However, for use in FT, maybe it would give you a little more accuracy.  Unfortunately, the LW barrel likely costs almost as much as the QB itself ???

Kirk

Scoped the gun last night and shot for groups today and am very pleased with its accuracy at least to 25 yards so may try the LW barrel just to see if it improves any. I already have the LW barrel and it only cost me 40 bucks from a fellow FT member so cost is not the issue. Here is a picture of the target at 25 yards and the flyers are me pulling the shots but there are 5 shots grouped within a 3/8" CTC group so its a shooter with the barrel it has now.

Mike
Title: Re: QB79 Ninja - The $200 PCP
Post by: SpiralGroove on February 28, 2016, 02:13:05 AM
Mike 8),
It will be interesting to see how much more the LW barrel can give you?


Title: Re: QB79 Ninja - The $200 PCP
Post by: Michael Loar on February 28, 2016, 04:05:10 AM
Kirk
I agree but that will come when its apart upgrading to the bottle kit since I only want to take it apart as little as necessary. I know a barrel swap is pretty easy if I am correct in its only the barrel band and set screw on top of breech that needs loosened/removed to slide the barrel out and in.  I have never had these apart yet so if I am missing a step please let me know what is required to change out barrels.

Mike
Title: Re: QB79 Ninja - The $200 PCP
Post by: SpiralGroove on February 28, 2016, 02:28:18 PM
Hey Mike,
That's it ............. not that hard. 
Yeah, I try NOT to take apart my guns too much as it becomes a whole day affair.  Replacing o-rings, lubing, bluing, or losing parts.

My shop bench is very messy after making my last LDC.  I don't dare do anything until the whole garage is cleaned and tools found :P.

(http://i113.photobucket.com/albums/n227/kirk_schwarz/IMG_1573_zpsdyfvlaem.jpg) (http://s113.photobucket.com/user/kirk_schwarz/media/IMG_1573_zpsdyfvlaem.jpg.html)

(http://i113.photobucket.com/albums/n227/kirk_schwarz/IMG_1579_zps1e2f43pi.jpg) (http://s113.photobucket.com/user/kirk_schwarz/media/IMG_1579_zps1e2f43pi.jpg.html)
Title: Re: QB79 Ninja - The $200 PCP
Post by: Michael Loar on February 28, 2016, 05:06:21 PM
Kirk
I thought I was bad about tools and parts on my workbench but now don't feel so bad since I have good company I see, LOL.

The funny thing is being a mechanic for 45 years and even though it looks very much the same I know exactly where every tool or part is on the work table. My bulk amount of tools are in the three tool boxes I have very organized, but the ones I tend to use most everyday just never seem to make it back into the boxes for long enough to be worth the effort to put them up and get them out.

It keeps my grandkids from messing with them since they cannot put them back just how they found them so that I don't know they were playing with them so there is some method to my madness, LOL.

Mike
Title: Re: QB79 Ninja - The $200 PCP
Post by: Michael Loar on February 28, 2016, 05:09:57 PM
Kirk
Is that a harbor freight lathe I see or if not what brand and size is it, how do you like it as I am in the market for a small work bench size lathe and would like some first hand experience with just what quality and performance the small ones like that give for the dollars they cost.

Your thoughts.

Mike
Title: Re: QB79 Ninja - The $200 PCP
Post by: SpiralGroove on February 28, 2016, 06:11:31 PM
Mike,
I absolutely love it.  It's the 12" Harbor Freight model.  I got it for 33% off, plus on sale - so I paid about $410 + shipping.  I originally got the 10", but it felt too cramped.  The 12" actually has a 14" bed.
I hadn't worked on a lathe since High School and really wanted to get back into making things.  It was my 54th birthday present in 2013. 

It has been a Godsend as far as tuning airguns.  I spent about 2 days refining the chuck, ways and Gibbs and generally cleaning off all the grease.  I think I need to look at adjusting again to better align the tail stock with the chuck.

Many people have knocked it's quality, but you should be able to do many things with it.  Out of the box, this lathe is pretty rough, but kind of like the QB78/79.  A little work goes a long way.

Good Luck ;)
Title: Re: QB79 Ninja - The $200 PCP
Post by: WECSOG on February 29, 2016, 12:34:45 AM
Hey Mike,
That's it ............. not that hard. 
Yeah, I try NOT to take apart my guns too much as it becomes a whole day affair.  Replacing o-rings, lubing, bluing, or losing parts.

My shop bench is very messy after making my last LDC.  I don't dare do anything until the whole garage is cleaned and tools found :P.

(http://i113.photobucket.com/albums/n227/kirk_schwarz/IMG_1573_zpsdyfvlaem.jpg) (http://s113.photobucket.com/user/kirk_schwarz/media/IMG_1573_zpsdyfvlaem.jpg.html)

(http://i113.photobucket.com/albums/n227/kirk_schwarz/IMG_1579_zps1e2f43pi.jpg) (http://s113.photobucket.com/user/kirk_schwarz/media/IMG_1579_zps1e2f43pi.jpg.html)

For a minute there, I thought you had somehow posted a photo of my workbench. Seriously!  ;D

I have the same mini-lathe, a similarly messy bench, and my propane torch even has a tank of the same blue color!

ETA: Actually, I have the 7x10. But I also have a Grizzly 9x19, so it's all good!
Title: Re: QB79 Ninja - The $200 PCP
Post by: Michael Loar on February 29, 2016, 01:06:04 AM
Mike,
I absolutely love it.  It's the 12" Harbor Freight model.  I got it for 33% off, plus on sale - so I paid about $410 + shipping.  I originally got the 10", but it felt too cramped.  The 12" actually has a 14" bed.
I hadn't worked on a lathe since High School and really wanted to get back into making things.  It was my 54th birthday present in 2013. 

It has been a Godsend as far as tuning airguns.  I spent about 2 days refining the chuck, ways and Gibbs and generally cleaning off all the grease.  I think I need to look at adjusting again to better align the tail stock with the chuck.

Many people have knocked it's quality, but you should be able to do many things with it.  Out of the box, this lathe is pretty rough, but kind of like the QB78/79.  A little work goes a long way.

Good Luck ;)

Kirk

Cool that's good to know and we have finally got a harbor freight here in town now so I would not have to pay shipping and will just wait for a 33% off and on sale as well.

I had a two year course in machining taught to me by a master machinist when I worked for Harley as a research and development mechanic so I know just how much fun and use I would get out of having one to make parts with. I have access to a friends shop at his house with a lathe and mill and do a lot of stuff there but having one in my own garage would just be icing on the cake.

My friend is wanting to sell his lathe and mill but they are big footprint items with the lathe being an old south bend 10x 48" model and the mill a huge upright one and I just don't have the room for the big footprints they command in my garage. I can get the lathe for 1000 bucks with all the attachments and its 40 years worth of attachments and cutters mills and such but just don't have a 4 foot area to place it and it only a 1 inch pass thru so while its plenty long enough it is limited in the diameter of material that it can machine and I know the small lathe is only a 3/4' pass thru but it also only takes up 2 feet of work bench if that. I have not ruled it out but will have some serious clean up to do to make room for it but would never have to buy any tooling or attachments for it since its already been bought. He did lots of gun barrel work over the 40 years he has had it.

Mike
Title: Re: QB79 Ninja - The $200 PCP
Post by: SpiralGroove on February 29, 2016, 02:29:53 PM
Yeah Mike,
The South Bend lathe is WAY WAY way better then the HF 12".

The whole thing only weighs about 100 lbs., so I bolted it through the underside of my bench for more stability.

The HF lathe is equivalent to a QB; whereas the South Bend is a RAW or Flex.
Title: Re: QB79 Ninja - The $200 PCP
Post by: Michael Loar on February 29, 2016, 02:37:16 PM
kirk
I agree 100% with the HF being a QB and the south bend being a RAW or Flex and the price is right but like I said its just got a huge footprint and will have to find room to put it some where as it would engulf my workbench so that it could not be used for anything but the lathe. Plus I don't see me ever making anything close to 4 feet in length that I need a lathe of that size.

Still not ruling it out yet though.

Mike
Title: Re: QB79 Ninja - The $200 PCP
Post by: rsterne on March 08, 2016, 07:05:04 PM
Recently one of our GTA members, Ribbonstone, noticed a slight bulging of the end of the tube on his QB79, in the thin area adjacent to the screw holes for securing the tank block.... The gun was operated for a time at 1250 psi.... In response, I have done an analysis of the tank block attachment, which is detailed in this thread....

http://www.gatewaytoairguns.org/GTA/index.php?topic=105712. (http://www.gatewaytoairguns.org/GTA/index.php?topic=105712.)

If you are building a QB79 HPA conversion of any kind, you should read that thread.... If you are using more pressure than the 1100 psi factory setting for a Ninja SHP regulator, I am now recommending that you pin the tank block with two additional 4mm or 8-32 screws, or a 5/32" shear pin, between the O-rings.... If you want to be more conservative, you might want to pin the block when using the SHP regulator.... or even with a standard 850 psi Paintball regulator.... Complete information is in that thread....

Bob
Title: Re: QB79 Ninja - The $200 PCP
Post by: Michael Loar on March 09, 2016, 02:19:07 AM
Bob
I have been following that thread with great interest and deciding on the method I will use to make my gun at least at a 3:1 safety margin if not 3.5:1 as I may go to 1500 psi output pressures from the pro SHP regulator. Like I have said my main goal is to get as close to a 20fpe FT hunter class gun as possible without exceeding that power limit so actually want 890 to 900 up to 920 fps with JSB 10.34s which is right at 18.6 to 19.44 fpe.

Right now just getting all materials on hand and formulating a plane to proceed.

Mike
Title: Re: QB79 Ninja - The $200 PCP
Post by: 454 Big Block Chevy on March 09, 2016, 09:45:32 AM
I'm looking at this, except in .177.  Interested completely!!!
Title: Re: QB79 Ninja - The $200 PCP
Post by: rsterne on March 09, 2016, 01:35:59 PM
You can build an EXCELLENT 20 FPE .177 cal around this platform.... Using the 10.3 gr. JSB Exact Heavies at right around 900 fps it was extremely accurate and delivered a ton of shots.... enough for an entire FT course with sighting in.... from a 13 CI tank.... Most FT guys find the accuracy is best with those pellets between 880-900 fps....

Bob
Title: Re: QB79 Ninja - The $200 PCP
Post by: Michael Loar on March 11, 2016, 04:57:15 AM
You can build an EXCELLENT 20 FPE .177 cal around this platform.... Using the 10.3 gr. JSB Exact Heavies at right around 900 fps it was extremely accurate and delivered a ton of shots.... enough for an entire FT course with sighting in.... from a 13 CI tank.... Most FT guys find the accuracy is best with those pellets between 880-900 fps....

Bob

Agreed 100% as far as velocity is concerned for the best accuracy with 10.3 JSBs and is why I want to build the gun as I have stated so I can sight in and shoot the entire match on one fill. I use a GEN 1 Mrod now tuned to shoot the JSBs at 890 to 910 fps for a 20 ES spread and get 50 shots per fill to 3100 psi down to 2100 psi with good results but its to heavy for me to hold steady in the off hand and kneeling lanes so that is why I am hoping to shave a couple pounds off with the QB and still get the accuracy and shot count to only fill once per match. Our monthly club matches are only 48 shots but a sanctioned match is 60 shot per day for two days so the QB would be ideal for that with the 13 ci bottle.

I have an extra FWB 300s stock that is broke at the knee and am going to see if it can be pinned or doweled and glued for repair so it can be inletted to accept the QB action for a nice FT stocked gun. 

Mike 
Title: Re: QB79 Ninja - The $200 PCP
Post by: 454 Big Block Chevy on March 11, 2016, 09:46:42 AM
You can build an EXCELLENT 20 FPE .177 cal around this platform.... Using the 10.3 gr. JSB Exact Heavies at right around 900 fps it was extremely accurate and delivered a ton of shots.... enough for an entire FT course with sighting in.... from a 13 CI tank.... Most FT guys find the accuracy is best with those pellets between 880-900 fps....

Bob

I have probably 10,000 Crosman 10.5 domes, all from the same lot, from when i had my Marauder.  I would shoot those for a good solid backyard plinker/starling buster.  if they shot accurate of course.  i really want to build this... would the regulator be better set at 1000 psi instead of 1200 for a .177 gun?
Title: Re: QB79 Ninja - The $200 PCP
Post by: nervoustrigger on March 11, 2016, 10:05:19 AM
What energy level are you wanting to achieve?
Title: Re: QB79 Ninja - The $200 PCP
Post by: 454 Big Block Chevy on March 11, 2016, 10:08:06 AM
honestly a 7.9 CPHP at 900 would be ideal for about 100+ shots.  but the SHP regulator would probably scoot a 7.9 a little faster than that, so i have the 10.5's i really like 900 fps as i am getting really good at learning distance drop at 900 fps.  and faster than that i get erratic accuracy with some pellets.
Title: Re: QB79 Ninja - The $200 PCP
Post by: nervoustrigger on March 11, 2016, 10:37:41 AM
That's virtually identical to how we have my son's QB79 tuned on a 1000psi setpoint.  Right at 900fps with 7.9gr, 875fps with 8.4gr, and 830fps with 10.3gr.  It's opened up pretty well for flow and has a skeletonized valve but if I were building one today, I would use the rear spring approach.  That is, an ink pen spring on the valve stem held by an E-clip, totally doing away with the front (aluminum) half of the valve.
Title: Re: QB79 Ninja - The $200 PCP
Post by: 454 Big Block Chevy on March 11, 2016, 10:43:49 AM
Well.  I am looking really hard at this setup.  Reading lots.  I would like a plug n play setup.  I don't want tobspend any time tuning.  I want a fun light weight backyard plinker that's cheap to shoot and accurate
Title: Re: QB79 Ninja - The $200 PCP
Post by: SpiralGroove on March 11, 2016, 10:49:29 AM
Hey Big Block,
I have found that the QB's really like boxed CPUM in 7.9 gr. or 10.5 gr. :D
JSB's might shoot a little better, but now you could put those pellets to good use.
Title: Re: QB79 Ninja - The $200 PCP
Post by: nervoustrigger on March 11, 2016, 11:59:42 AM
Well, cheap and accurate and no time tuning isn't a realistic mix.  It's kinda like the racing adage of cheap, fast, and reliable...pick any two.

That said, if you do the right set of mods, there shouldn't be much tuning required in terms of getting good efficiency and low ES.  Doing the RVA mod or a SSG will help immensely. 
Title: Re: QB79 Ninja - The $200 PCP
Post by: Michael Loar on March 11, 2016, 04:40:44 PM
All the fun is in the tuning and tinkering to get the satisfaction of doing it yourself

Mike
Title: Re: QB79 Ninja - The $200 PCP
Post by: SpiralGroove on March 11, 2016, 05:08:43 PM
Yeah,
For me the "tinkering/tuning part" is very satisfying, that's why US afflicted tend to go from project to project ::).  With of course, a short break in between.  Once you're satisfied the gun is finished, all frustration (if any) experienced throughout the project, seems to vanish.

I just need to work on drilling more precise holes with my drill press :P

(http://i113.photobucket.com/albums/n227/kirk_schwarz/IMG_1592_zpsowmvagzk.jpg) (http://s113.photobucket.com/user/kirk_schwarz/media/IMG_1592_zpsowmvagzk.jpg.html)

Title: Re: QB79 Ninja - The $200 PCP
Post by: wll2506 on March 11, 2016, 11:06:53 PM
You can build an EXCELLENT 20 FPE .177 cal around this platform.... Using the 10.3 gr. JSB Exact Heavies at right around 900 fps it was extremely accurate and delivered a ton of shots.... enough for an entire FT course with sighting in.... from a 13 CI tank.... Most FT guys find the accuracy is best with those pellets between 880-900 fps....

Bob

I'm getting ~880fps with 10.5 Kodiaks ... I'm going to empty her tomorrow and put in a margin of safety though.

wll
Title: Re: QB79 Ninja - The $200 PCP
Post by: Michael Loar on March 12, 2016, 02:33:25 AM
Yeah,
For me the "tinkering/tuning part" is very satisfying, that's why US afflicted tend to go from project to project ::).  With of course, a short break in between.  Once you're satisfied the gun is finished, all frustration (if any) experienced throughout the project, seems to vanish.

I just need to work on drilling more precise holes with my drill press :P

(http://i113.photobucket.com/albums/n227/kirk_schwarz/IMG_1592_zpsowmvagzk.jpg) (http://s113.photobucket.com/user/kirk_schwarz/media/IMG_1592_zpsowmvagzk.jpg.html)

Kirk
That is some of the challenge that leads to the satisfaction of using equipment that makes it challenging and resourceful to do good work with mediocre tools and equipment. I use my 35 year old craftsman 8 inch drill press as a mill more than a drill press and have already bent one spindle from doing so but 30 bucks later and its back ticking and taking a licking just like my old Timex.

Got to get a lathe next for sure. Been watching HF for a sale and figuring out if I can find room for that old south bend somewhere in my garage.

Mike
Title: Re: QB79 Ninja - The $200 PCP
Post by: SpiralGroove on March 12, 2016, 03:12:38 AM
Well the drilling part maybe my bad :P

I have the massive Grizzly floor standing drill press.  It's a tank at 300lbs+. My biggest problem is the 5/8" chuck has a hard time with smaller bits.  I also need to upgrade my bits from the cheap HF ones.
My skill using my 6" HF cross slide vise also needs to be improved.

In short, I had to drill 3/16" holes (4.7mm) for my 4mm screws to fit. This left the holes > than 1/32" closer to the front than a tight fit.

Putting in a pin or buying another tube is a "No Brainer" compared to an explosion.   
Title: Re: QB79 Ninja - The $200 PCP
Post by: Michael Loar on March 13, 2016, 03:11:37 AM
kirk
I fully understand the drilling on a old drill press with a substandard vise that moves while drilling on its own accord so that's the challenging part I was referring to as my drill press is 35 years old and I have one of those Cummings tool vices and the HF drill bit as well so we just have to do the best we can and measure there or four times and cut once hoping its right the first time. LOL

Mike
Title: Re: QB79 Ninja - The $200 PCP
Post by: birdmove on March 13, 2016, 03:28:02 AM
I have a question, and I am not one that has done a bunch of modifications to my airguns. I have replaced the plastic breeches with steel ones on my 1377, 1322, and 2240 (though the 2240 is badly hanging up the pellets as I try to load it, so I have to sort that out).  But, I am interested in the basic conversion of a QB79, with the Ninja air tank. From what I'm reading, all I really need is the basic QB79, and the Ninja tank, and it's ready to shoot? It says that the barrel must be removed, or slid forward, so that the tank can be screwed into the airgun.  So, once the tank is in place, does this mean that it can then be filled (via air pump or whatever) WITH the tank still in place on the gun? So the barrel only needs to be removed for the initial tank installation, then you are good to go?

    Is barrel removal very similiar to on a 1377/1322/2240?   And, last, does this Ninja tank have a drain valve to exhaust the air should the gun need to be worked on safely?

    Thanks for any comments. I just want to be sure I understand what I might be getting into here.

   
Title: Re: QB79 Ninja - The $200 PCP
Post by: SpiralGroove on March 13, 2016, 04:32:16 AM
Hey Birdmove,
1) Yes, Gun, Tank, Fill & Pellets.
2) Yes, Single set-screw on top of breach needs to be loosened or removed to pull out barrel.
3) Once barrel removed, put small amount of Super-Lube on Ninja Tank seal and screw in.
4) You may need to replace the 3 barrel o-rings depending condition, use Super-Lube again.
5) Keep tank on gun when filling. I rarely remove the tank ;).
6) Fill tank to 200 bar with hand pump or large tank.  I only occasional bleed the tank.  To do so, I just back out the 1.8K bust disk slightly - be careful this disk can become a projectile.
7) I don't know about the other models, but the barrel needs to be turned and twisted as the three o-rings hold it in place.  This is pretty easy.  Also, remove rear sight and loosen barrel band.

Good Luck :D

Title: Re: QB79 Ninja - The $200 PCP
Post by: Michael Loar on March 13, 2016, 07:37:39 AM
Hey Birdmove,
1) Yes, Gun, Tank, Fill & Pellets.
2) Yes, Single set-screw on top of breach needs to be loosened or removed to pull out barrel.
3) Once barrel removed, put small amount of Super-Lube on Ninja Tank seal and screw in.
4) You may need to replace the 3 barrel o-rings depending condition, use Super-Lube again.
5) Keep tank on gun when filling. I rarely remove the tank ;).
6) Fill tank to 200 bar with hand pump or large tank.  I only occasional bleed the tank.  To do so, I just back out the 1.8K bust disk slightly - be careful this disk can become a projectile.
7) I don't know about the other models, but the barrel needs to be turned and twisted as the three o-rings hold it in place.  This is pretty easy.  Also, remove rear sight and loosen barrel band.

Good Luck :D

Birdmove
Everything SpiralGroove said plus with stock ninja regulator it will be possibly required to not fully tighten tank into the block on the gun so that the regulator burst discs or gauge or fill fitting don't contact the barrel since the threads in the tank block are all started at different points so that it may result in contact between those parts on the regulator and the barrel.

It is not that likely but can happen to tighten up that way so just loosen enough for clearance or get a Ninja Pro SHP regulator that allows you to rotate the regulator body to the desired position of your choice.

Mike
Title: Re: QB79 Ninja - The $200 PCP
Post by: sr1sws on March 13, 2016, 09:04:32 AM
+1 on using the SHP Pro.

Odds are the barrel o-rings will be wrecked when removing the barrel - size 012.  Deburr the breech while the barrel is out and reinstall with your favorite silicone grease - Super Lube, swimming pool o-ring grease, dielectric grease, scuba o-ring grease, plumbers o-ring grease - they all work.

Oh - stock up on pellets - the QB's have quite the appetite.

Steve
Title: Re: QB79 Ninja - The $200 PCP
Post by: nervoustrigger on March 13, 2016, 11:22:31 AM
FYI, there is no need for the bonnet to be fully bottomed out against the tank block.  Back it off a fraction of a turn until the fill nipple and gauge are in a good position and then pressurize it.  Once pressurized, the load on the threads keeps it from rotating.  You can put in some shim stock if it makes you feel better but it is no more safe either way.
Title: Re: QB79 Ninja - The $200 PCP
Post by: Michael Loar on March 13, 2016, 01:32:51 PM
FYI, there is no need for the bonnet to be fully bottomed out against the tank block.  Back it off a fraction of a turn until the fill nipple and gauge are in a good position and then pressurize it.  Once pressurized, the load on the threads keeps it from rotating.  You can put in some shim stock if it makes you feel better but it is no more safe either way.

Jason
I was not trying to infer that the bottle and reg not being fully tight was unsafe as you are correct once pressurized it will not turn, but just that SHP reg allows for rotation to place fill nipple and gauge on which ever side you prefer it to be for fill convenience. plus its a Belleville washer reg not spring reg  which I just prefer myself.

Mike   
Title: Re: QB79 Ninja - The $200 PCP
Post by: rsterne on March 13, 2016, 01:50:41 PM
Something for you guys to consider if you are making a tube to hold a QB79 or similar tank block.... Instead of cutting the tube to length first, and then trying to lay out and drill the screw holes the correct distance from the end.... simply reverse the process.... Figure out where you want the tank block, lay out the screw holes, and just drill straight through, horizontally.... THEN cut the tube off with at least 1/8" clearance to the holes, so that when you insert the tank block you can't quite get the screws in.... The use a belt sander, lathe, grinder, or even a hand file to carefully and slowly shorten the tube, keeping the end square, until you can just get the screws to thread into the block.... This will leave the maximum amount of metal past the screw holes possible.... Don't make it so tight that you damage the screws, but if done right, you will have virtually no gap between the end of the tube and the tank block, and maximum strength....

My Dad always used to say, do the most difficult part of the job first, and then the rest is easy....

Bob
Title: Re: QB79 Ninja - The $200 PCP
Post by: nervoustrigger on March 13, 2016, 02:46:15 PM
Jason, I was not trying to infer that the bottle and reg not being fully tight was unsafe...

Yeah, sorry I wasn't more clear.  I didn't think you were saying or implying it was unsafe.  Since we have been putting an emphasis on safety, I just wanted others to know that backing it off a fraction of a turn is perfectly fine and does not compromise safety or function.
Title: Re: QB79 Ninja - The $200 PCP
Post by: soarwitheagles on March 13, 2016, 03:29:44 PM
Hi everyone!

I just picked up the Beeman QB78 from a local Big 5 for under $100.

Is there anyone in the Sacramento area that can do the mod for me for a reasonable amount of $$$?

I have no machine shop tools or skills.

Thanks,

Soar
Title: Re: QB79 Ninja - The $200 PCP
Post by: Michael Loar on March 13, 2016, 04:10:17 PM
Bob
That's an excellent idea of drilling first then cut and fine tune to fit for a perfect snug and professional look and actually I would say better than factory fit for sure. Glad I have had other projects ahead of mine so I have yet to cut and drill.

Mike
Title: Re: QB79 Ninja - The $200 PCP
Post by: Michael Loar on March 13, 2016, 04:19:21 PM
Jason
No harm no foul as I should have included the statement that the bonnet being a small distance from fully seated was still safe as well. I tend to take thing for granted since being a mechanic it is just second nature to put safety first.

Still have all my toes and fingers although I have had a few mistakes early on in my career that removed some meat from a couple fingers but healed quite well. I always was fascinated by the human muscular skeleton structure and had to get a closer look for myself when I was still 10 foot tall and invincible and felt no pain. LOL

Try right index finger going thru a Pinto timing belt and cam gear with the engine running while listening for a noise with the timing cover off with a stethoscope.

Mike   
Title: Re: QB79 Ninja - The $200 PCP
Post by: wll2506 on March 13, 2016, 04:26:30 PM
Hi everyone!

I just picked up the Beeman QB78 from a local Big 5 for under $100.

Is there anyone in the Sacramento area that can do the mod for me for a reasonable amount of $$$?

I have no machine shop tools or skills.

Thanks,

Soar

Soar you are doing the right thing. If I did not have the tools at the office to do the work on these guns, i surely would not have tried it. The Qb78 from big five can turn into a monster of a gun, I have two of them, but it does take a lot of elbow grease and the equipment and fittings to do it.

I can tell you before I modded my QB78, I used her with CO2 and she was lots of fun to shoot.. I also knocked the heck out of some pest starlings around a buddies farm at 20 or so yards using CPHP pellets.

Best bet is if you are in doubt, don't take a chance ... you are playing with 3000psi, which is a small bomb if things go wrong !

wll