ScopesAndAmmo.com Store Logo

+ Reply to Thread
Page 1 of 2 12 LastLast
Results 1 to 10 of 14

Thread: QB78d long Co2 tube

  1. #1
    Member just missed's Avatar
    Join Date
    Sun Jan 1 2012
    Location
    Ottawa
    Posts
    31

    QB78d long Co2 tube

    Planning on bulking my QB78d and would like to add a longer main tube, more shots and I don't want to cut my new stock. I there a direct fit tube out there, sticking with Co2.

    John

  2. #2
    Senior Member SeanMP's Avatar
    Join Date
    Thu Dec 22 2011
    Location
    Just south of "Out There"
    Posts
    911
    Sean

  3. #3
    Member just missed's Avatar
    Join Date
    Sun Jan 1 2012
    Location
    Ottawa
    Posts
    31
    I saw this during my search, is there a issue using this tube for Co2?

  4. #4
    Administrator AirGunEric's Avatar
    Join Date
    Sat Dec 3 2011
    Location
    Somewhere Out There
    Posts
    1,295
    Other than it being twice as strong as it needs to be for Co2, no.
    I'd say I care- but I'd probably be lying...


  5. #5
    Member just missed's Avatar
    Join Date
    Sun Jan 1 2012
    Location
    Ottawa
    Posts
    31
    Order placed, maybe one day I'll make the leap to HPA

  6. #6
    Senior Member SeanMP's Avatar
    Join Date
    Thu Dec 22 2011
    Location
    Just south of "Out There"
    Posts
    911
    On the QB's it's a really easy leap...more like a tiny step.

    When you assemble the gun just use silicone grease/lube and nothing else. Then switching to HPA is as simple as filling it with HPA.
    Sean

  7. #7
    Member daguasta's Avatar
    Join Date
    Mon Feb 20 2012
    Location
    brantford
    Posts
    49
    Quote Originally Posted by SeanMP View Post
    On the QB's it's a really easy leap...more like a tiny step.

    When you assemble the gun just use silicone grease/lube and nothing else. Then switching to HPA is as simple as filling it with HPA.
    is not the pressure limited to 1500 psi tho?
    unless further mods are made?
    Everyone is entitled to an opinion ...but only mine is right!
    DAVE G

  8. #8
    Senior Member SeanMP's Avatar
    Join Date
    Thu Dec 22 2011
    Location
    Just south of "Out There"
    Posts
    911
    well I've stretched it as far as 1800psi. The limiter is the hammer/hammer spring. Bob has a fair bit of data on mods and pressures.

    You also want to give the valve to valve stop block clearance a quick check if your planning on going to very high pressures. Ideally this clearance should be as tight as possible. I epoxied a thin shim washer onto my stop block.
    Sean

  9. #9
    Moderator rsterne's Avatar
    Join Date
    Wed Dec 7 2011
    Location
    Coalmont, BC
    Posts
    1,266
    I would stay under 1800 psi on HPA with a QB.... CO2 can reach that pressure at 120*F, so IN THEORY the gun should be able to handle that.... The problem with regulated HPA is that if you have a regulator failure the gun will see whatever pressure is in the tank.... would could easily be 3000 psi.... even 4500 if you are using a 300 bar Carbon tank.... I would highly recommend that if you are using HPA on a QB that you make sure there is a 1.8K burst disc on the downstream side of the regulator.... That limits you to about 1500-1600 psi so you won't blow the disc.... If you are only filling with a hand pump, I might consider using 1800 psi.... but you will need to shim the hammer spring, replace it, or increase the hammer strike in some way to use that much pressure....

    Bob
    Dominion Marksman Silver Shield - 5890 x 6000 in 1976, and downhill ever since!
    Airsonal: Too many to count!

  10. #10
    Senior Member SeanMP's Avatar
    Join Date
    Thu Dec 22 2011
    Location
    Just south of "Out There"
    Posts
    911
    Bob, I think the question was what do you have to do to utilize the full potential of the aftermarket 3000 psi tube. I can't comment on any specifics beyond the stock tube
    Sean

+ Reply to Thread

Similar Threads

  1. 3000 psi tube QB78
    By remtom1200 in forum Co2 and Pre-Charged Pneumatic (PCP) guns.
    Replies: 64
    Last Post: Feb 17 2012, 04:01 AM
  2. Replies: 3
    Last Post: Feb 12 2012, 08:28 AM
  3. 2240 and QB78D Custom Grips and Stock
    By Merlyn in forum Customization and Craftsmanship
    Replies: 4
    Last Post: Jan 30 2012, 01:01 PM
  4. QB78D? There's one that may be better coming- the Xisico XS60C
    By AirGunEric in forum Co2 and Pre-Charged Pneumatic (PCP) guns.
    Replies: 30
    Last Post: Jan 22 2012, 07:23 AM
  5. Long distance shooting, how do you feel about wind?
    By chronic in forum Airgun Target Talk
    Replies: 15
    Last Post: Jan 21 2012, 12:33 PM

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts