Old question of changing qb into pcp with kit

Old question of changing qb into pcp with kit

Joined: December 21st, 2005, 7:18 am

May 18th, 2012, 6:22 am #1

Hi,


I found that one can still buy a jack haley pcp tube that converts the co2 qb78 into a pcp qb 78. Has anyone done this or used a similar kit?

I am aware of loads of people using the HPA bottle. Not trying or meaning to be rude but I would really like to know about the tube conversion kits.

Been thinking about getting a new pcp or doing the kit upgrade to my rifle. I've had it for so long that I can shoot well with it and am very addicted to it(scope, pellets and everything working in perfect harmony).


Warm Regards,

1008mod
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Joined: November 17th, 2006, 3:51 am

May 18th, 2012, 11:14 am #2

Guess quite a few of us have managed a PCP QB in one form or another.

In its simplest form:

All the smoothing/alignment/deburing mods outlined in the co2 tunes. New PCP tube shouldn't need to be smoothed/deburred.

Modding the valve a bit to make it a simpler non-piercing Delrin seal design (the issue valve stem doesn't live long at pressures higher than Co2 and the piercing pin assembly just clutters the air flow). If power is a goal, would search past posts on increasing the valve gas flow.
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Increasing striker hit to the valve in ordere to operate at higher than co2 pressures.

HAd used the same PCP tube on a .177...then used it on a .22...ended up with this long barreled .25 that pretty well followed the above.
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Joined: December 21st, 2005, 7:18 am

May 19th, 2012, 5:51 am #3

Nice work there Bob. I was wondering more about the kit sold by Jack Hailey. Is that an easy conversion?
Thank you so much for the eye candy of your rifle. Wish I had a .25 but pellets are such a problem here.


Warm Regards,

1008mod
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Joined: November 17th, 2006, 3:51 am

May 19th, 2012, 2:07 pm #4

..have seen some finished rifles, and the quality is high...so suspect his tubes are top notch.

I'd have to ask him...call or email...as I'm not sure what "extra" needs there might be.

For DIY use, a pressure rated tube, with all the holes and slots in the right place, and new end cap would be the start point. Could do the valve work, assembly, adjusting, and tuning.

Don't see a .25 as a good choice in a "do everything" PCP. Really, the only good reason for a .25 is power...if you don't need the power, can certainly use a .177 or .22. Kept that one simple, and once it got to +50 foot pounds, I quit playing with it. I certainly do not need a 50 foot pound .25 to plink with, shoot pest birds with, or hunt tree squirrels with. The only real use I have is to occasinally take out a big critter...so it really covers about 5% of my hunting.
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Joined: March 28th, 2002, 6:54 pm

May 19th, 2012, 4:52 pm #5

Hi,


I found that one can still buy a jack haley pcp tube that converts the co2 qb78 into a pcp qb 78. Has anyone done this or used a similar kit?

I am aware of loads of people using the HPA bottle. Not trying or meaning to be rude but I would really like to know about the tube conversion kits.

Been thinking about getting a new pcp or doing the kit upgrade to my rifle. I've had it for so long that I can shoot well with it and am very addicted to it(scope, pellets and everything working in perfect harmony).


Warm Regards,

1008mod
assembly. I removed the cap, radiused the tube edge, and replaced the o-ring. That, and the very basic high power setup of the valve were the only issues..it's a well made piece.

After many hours of tuning,including a whole new valve and lightened striker, I have mine producing 30 shots between 900 and 930 fps using .20 benjamin pellets (14.3 grains?)I think its time to tune it down a bit, to the 870 fps range.
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Joined: June 21st, 2009, 8:05 pm

May 19th, 2012, 8:43 pm #6

Hi,


I found that one can still buy a jack haley pcp tube that converts the co2 qb78 into a pcp qb 78. Has anyone done this or used a similar kit?

I am aware of loads of people using the HPA bottle. Not trying or meaning to be rude but I would really like to know about the tube conversion kits.

Been thinking about getting a new pcp or doing the kit upgrade to my rifle. I've had it for so long that I can shoot well with it and am very addicted to it(scope, pellets and everything working in perfect harmony).


Warm Regards,

1008mod
It comes with a stock valve and the hammer spring supplied is oversize. But its a good quality tube, and a great price. I plan on getting one of his big bore barreled actions and building another.

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http://www.cafepress.ca/AK47andmore
Last edited by captiveherps on May 19th, 2012, 8:45 pm, edited 1 time in total.
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Joined: December 21st, 2005, 7:18 am

May 21st, 2012, 5:34 am #7

Thanks you for replying Scot, James and Bob. James your pictures have actually revealed how high quality his stuff is and really worth the $175, course shipping will be an additional thing. What this mod will do is give me an almost new air rifle without the hassle of importing another pcp. Now that it is a hundred degrees in the shade you will be amazed how much my QB barks on Co2.

Thanks once again.

1008mod
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Joined: June 21st, 2009, 8:05 pm

May 21st, 2012, 10:37 am #8

You will be amazed how loud it is on HPA.

http://www.cafepress.ca/AK47andmore
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