Classic RT question

Collapse
X
 
  • Time
  • Show
Clear All
new posts
  • Jordan
    I. Am. Canadian. πŸ‡¨πŸ‡¦
    • Jul 2020
    • 3510
    • Southern Ontario, Canada

    #1

    Classic RT question

    I attempted to chrony my RT yesterday and noticed if I did the AGD procedure (fire, hold down trigger, fire again immediately after release, check speed) it shot a fairly consistent 260FPS. If I chronoed it how I would anything else, it shot 320FPS.

    I'm running a new lvl10 setup with gold spring, all new seals in everything, and a Ninja SHP tank with all the shims out currently (roughly 900-ish psi output).

    Am I doing something incorrectly or does it just need to break in?
  • Spider!
    MCB Member
    • Jul 2020
    • 541
    • Houston

    #2
    Does it RT? The bypass o-rings can be sticky and sluggish when new, making that quick recharge really weak. Until it starts to RT, I wouldn't worry about the release-pull type of shooting. Once it starts to RT, you don't want it to shoot-up too much. When it gets cooking, you can see the stream of paint start to flatten out as it picks up speed, changing your elevation to the target.
    Feedback

    https://www.mcarterbrown.com/forum/b...der-s-feedback

    Comment

    • Jordan
      I. Am. Canadian. πŸ‡¨πŸ‡¦
      • Jul 2020
      • 3510
      • Southern Ontario, Canada

      #3
      Originally posted by Spider!
      Does it RT? The bypass o-rings can be sticky and sluggish when new, making that quick recharge really weak. Until it starts to RT, I wouldn't worry about the release-pull type of shooting. Once it starts to RT, you don't want it to shoot-up too much. When it gets cooking, you can see the stream of paint start to flatten out as it picks up speed, changing your elevation to the target.
      No, not much RT action right now. The trigger actually felt much better before I replaced all the seals, so I figured it just needed break-in, but this is the first non-Classic Mag I've owned/used so I wasn't sure if I was on the right track.

      Comment

      • nak81783
        Last of the Salzburg Clan
        • Feb 2021
        • 593
        • DeWitt, MI

        #4
        In my opinion, you should continue using the chronograph procedure you described. It may have provided the very info needed to pinpoint your issue.

        Based on the information you provided, start by thoroughly cleaning and oiling #11 (regulator seat) and the surfaces it contacts. If that does't work, change that o-ring out, and thoroughly oil the new o-ring prior to installation.



        This will help you troubleshoot as well.



        Please let us know how it turns out.

        Comment

        • Jordan
          I. Am. Canadian. πŸ‡¨πŸ‡¦
          • Jul 2020
          • 3510
          • Southern Ontario, Canada

          #5
          Originally posted by nak81783
          In my opinion, you should continue using the chronograph procedure you described. It may have provided the very info needed to pinpoint your issue.

          Based on the information you provided, start by thoroughly cleaning and oiling #11 (regulator seat) and the surfaces it contacts. If that does't work, change that o-ring out, and thoroughly oil the new o-ring prior to installation.



          This will help you troubleshoot as well.



          Please let us know how it turns out.
          The seals are all brand new, replaced with an AGD kit. I even pulled the valve apart at the field to verify the state of the seals and that there was sufficient oil present, as well as no dirt or other contaminants.

          How does consistent high velocity when chronoing normally vs low velocity when using the RT chronograph method help? What might that indicate? Slow recharge, as Spider! noted?

          Comment

          • nak81783
            Last of the Salzburg Clan
            • Feb 2021
            • 593
            • DeWitt, MI

            #6
            First to answer your question: Using the AGD method, the #15 and #16 o-rings isolate the dump chamber from the effects of a leaking #11 o-ring. The non-AGD method does not, so higher pressure air gets into the dump chamber, increasing velocity.

            Under properly operating conditions, the valve can cycle 26 bps without shoot down, so even if it were in need of break-in, let's say it's operating at 1/3 speed, that's still almost 9 bps. I doubt you're pulling the trigger much faster than that (single shot at speed equivalent to 9 bps) while chronographing with the AGD method. Furthermore, your tank is around 900 psi. That's pushing directly on the top of the on/off pin between shots. Assuming a completely empty dump chamber (which it never really is), that comes out to over 9 lbf pushing the pin down (I hope I got my math right). I doubt pin stick can resist that much pressure/force.

            I very well could be wrong, those are just the reasons I'm focusing on the #11 o-ring rather than slow recharge. In my experience, the #11 o-ring is much more sensitive to lack of oil, debris, or just a bad o-ring (new o-rings can be bad, it happens). I've had a fiber from a cotton swab used to clean that o-ring and mating surfaces remain on the o-ring, causing the same issues you're describing.

            So I'd very much recommend another look at the #11 o-ring. Clean, re-oil, and try it again. If that doesn't work, replace that o-ring with another new, clean, and well-oiled o-ring.

            If that doesn't work, let us know the following, please:
            1. Is the 320 fps consistent, no matter how long you let it sit between shots?
            2. If you let it sit for a few minutes, with trigger released, does it leak out the back where you put the wrench to adjust velocity?
            3. Is there any leaking out the tiny hole on the side of the valve? If so, does it leak when the trigger is held back, released, or both?
            4. What's the length of your on/off pin?

            Finally, I'd like to amend/clarify my recommended chronograph procedure. You should do both methods. They should be relatively close, the AGD method perhaps a bit higher, but not the 60 fps spread you're seeing. That indicates a problem, which is why I recommend both methods - it detects problems.

            In my opinion, AGD did a great job engineering troubleshooting/safety into the valve. It's amazing what you can diagnose with a combination of trigger back/forward, where you hear leak(s) relative to trigger position, and velocity consistency (or lack thereof).

            Comment

            • Jordan
              I. Am. Canadian. πŸ‡¨πŸ‡¦
              • Jul 2020
              • 3510
              • Southern Ontario, Canada

              #7
              I'll note my results next time I'm out and report back... thanks for the replies, gentlemen.

              Comment

              • Brokeass_baller
                Pick it up!
                • Jul 2020
                • 1129
                • Ohio

                #8
                I have an oddball question, but it's something I've run into myself. Have you changed your air fittings recently? Notably, the elbows? The street elbows with the short female and the long male sides have about 3 threads until you start blocking the air hole. I had MASSIVE shoot down on an RT valve caused by threading the line in too far and blocking those holes. I backed them out and sealed the lines with loc-tite instead and everything has been normal. The problem had me scratching my head for some time.
                Feedback

                Comment

                • Jordan
                  I. Am. Canadian. πŸ‡¨πŸ‡¦
                  • Jul 2020
                  • 3510
                  • Southern Ontario, Canada

                  #9
                  Originally posted by Brokeass_baller
                  I have an oddball question, but it's something I've run into myself. Have you changed your air fittings recently? Notably, the elbows? The street elbows with the short female and the long male sides have about 3 threads until you start blocking the air hole. I had MASSIVE shoot down on an RT valve caused by threading the line in too far and blocking those holes. I backed them out and sealed the lines with loc-tite instead and everything has been normal. The problem had me scratching my head for some time.
                  I don't think I have the elbows in much further than that.

                  I really haven't used this RT much yet, it's been a project that I'm slowly fixing up/piecing together and my first non-Classic valved Mag and first lvl10 Mag.

                  Comment

                  • Jordan
                    I. Am. Canadian. πŸ‡¨πŸ‡¦
                    • Jul 2020
                    • 3510
                    • Southern Ontario, Canada

                    #10
                    2 month update.

                    - I revised my hose routing and ASA setup, and tore down the valve to verify oring condition and cleanliness. I did find a bit of what looked like dried Loctite debris in the reg pin assembly so I cleaned everything out again, and applied oil liberally during assembly.

                    - I also verified on-off pin length - 0.738, too short so bought and installed a 0.750 pin - and installed a stock CF frame and a new sear. I still had the old-style sear with carbide insert, and I was having trigger reset issues as well.

                    - I ditched my Cocker barrel adapter for a twistlock with a modified detent.

                    - I reinstalled my lvlX and tuned it properly.

                    Net result? A Mag that actually chronies, functions properly, and doesn't break paint. I think with some break-in and a 900 psi output tank I should have it RTing right where I want it, around the 10bps mark.
                    Last edited by Jordan; 08-09-2021, 01:21 PM.

                    Comment


                    • Tinybear
                      Tinybear commented
                      Editing a comment
                      Can’t wait to see it hit the field.

                    • Jordan
                      Jordan commented
                      Editing a comment
                      Me too - I've had it for a year and it's finally cooperating after multiple new parts. Yet the XMag that sat in a closet for 3 years needed a top on-off oring to be functional. πŸ™‚
                  Working...