G
Thamks for this. Currently replacing o-rings. Started off at the end of tank.. replaced leaky seal.. just to fill up and find out I have a reg leak out of hole of tube. Once tank loses all air.. I find that it pretty much ****s all other o-rings.
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Dang Chuck, that's perfect timing 
. I just developed a slow leak on my new Wildcat (10 -15 bar a day).... After 5000 pellets without the smallest hiccup I felt the time was right for me to do some air-gun tuning, which I have never done. Go figure, I tuned my gun to have a leak 
.
Your secret manual will come in handy, but all I ever touched was he hammer spring adjuster and the AMP regulator, so I am pretty sure I messed up some regulator o-ring. I will spray the vent/AMP adjusting hole with some leak detector, so we'll see.
Chuck, I have a question for you if I may; I was trying to get the JSB heavies to fly at 880fps. Problem is, if I adjust reg pressure above 135bar then I will get no fps increase because I don't have more hammer spring available (the HS nut is maxed out / all the way in), do I need a stronger spring and/or heavier hammer?
Christian
. I just developed a slow leak on my new Wildcat (10 -15 bar a day).... After 5000 pellets without the smallest hiccup I felt the time was right for me to do some air-gun tuning, which I have never done. Go figure, I tuned my gun to have a leak .Your secret manual will come in handy, but all I ever touched was he hammer spring adjuster and the AMP regulator, so I am pretty sure I messed up some regulator o-ring. I will spray the vent/AMP adjusting hole with some leak detector, so we'll see.
Chuck, I have a question for you if I may; I was trying to get the JSB heavies to fly at 880fps. Problem is, if I adjust reg pressure above 135bar then I will get no fps increase because I don't have more hammer spring available (the HS nut is maxed out / all the way in), do I need a stronger spring and/or heavier hammer?
Christian
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Great post, Chuck
Another one you can add to the list:
I used to have a Wildcat -MK1 .22 cal.
One day I noticed velocity dropping so I put it over my chrono.
JSB 18s were running at around 650 FPS instead of 890. What the heck?
Traced it to the barrel being rotated off it's detent and blocking the transfer port.
Probably from me screwing the moderator on too tight.
Something for WC owners to keep an eye on
Matt
Another one you can add to the list:
I used to have a Wildcat -MK1 .22 cal.
One day I noticed velocity dropping so I put it over my chrono.
JSB 18s were running at around 650 FPS instead of 890. What the heck?
Traced it to the barrel being rotated off it's detent and blocking the transfer port.
Probably from me screwing the moderator on too tight.
Something for WC owners to keep an eye on
Matt
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Wouldn't opening up the hole in the pellet probe make the depth less of a factor? Also a pin probe solves this issue.
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Chuck, the AMP reg came preset at 125bar (I was informed but never checked it), A quarter turn should yield 5bar (again, I was informed but I never verified it).
But but but, my hammer spring, hammer nut and hammer is all good now. I used your tuning secrets. The problem was: "Check that the measurement from the side of the breechblock to the end part of the feeding pin is between 28,55-28,8",,, I tried with 28,6 and speed dropped to 300fps - 28,7 speed 500fps - 28,8 and speed went up to 700fps - then I went 28,9 and speed went up 980fps 
, I was testing with jsb 25,4gr. So thank you very much for your secrets, I will soon be a master tuner myself 
I actually ordered a reg tester last week (from Huma). Now I just have to find my slow leak, which most probably is the AMP reg as I really cranked it up and down a lot during the last week.
Thanks again Chuck
But but but, my hammer spring, hammer nut and hammer is all good now. I used your tuning secrets. The problem was: "Check that the measurement from the side of the breechblock to the end part of the feeding pin is between 28,55-28,8",,, I tried with 28,6 and speed dropped to 300fps
- 28,7 speed 500fps - 28,8 and speed went up to 700fps - then I went 28,9 and speed went up 980fps , I was testing with jsb 25,4gr. So thank you very much for your secrets, I will soon be a master tuner myself I actually ordered a reg tester last week (from Huma). Now I just have to find my slow leak, which most probably is the AMP reg as I really cranked it up and down a lot during the last week.
Thanks again Chuck
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Thanks for the offer, but i'm all set on o-rings. I will go on a search and repair mission during the week-end, I hope my search will be over before the daunting task of pulling out the valve seat.
All the best to you.
All the best to you.
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