FX impact 22 reg setting low

Forums PCP Airguns FX impact 22 reg setting low

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    Hudo
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    Hey all. Finally got the chrono up and found the fx.isnon the piss. It is scraping 900fps at 100bar then getting progressively slower as I increase up to 150. I'm thinking maybe the gage is on the turps and false reading really low * I've already ordered a new one. Any one else had this happen?

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    ackuric
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    The valve becomes harder to open as you increase regulated pressure, so IF there isn't enough hammer strike, what you are observing may occur, although other issues may be at play…did you try to change power wheel settings or anything during this test? Does the hammer spring seem to be in good shape? Hope this helps.

     

    -Matt

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    sonny
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    What he said^^^^^

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    sonny
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    I was a little unsure about buying a impact because of the problems reported on them and was told by the dealer it was mostly owner error so i bought mine and it has preformed flawlessly for 2 yrs now. I didnt mess with the settings for a while until i felt i understood them better.

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    BDX
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    Hudo

    It is scraping 900fps at 100bar then getting progressively slower as I increase up to 150. I'm thinking maybe the gage is on the turps and false reading really low * I've already ordered a new one. Any one else had this happen?

     

    I cant imagine that the stock FX Impact hammer would have issues overcoming the Impacts valve spring tension at pressure below 145Bar. Perhaps the valve spring adjuster on the Impact is not "playing well with others".  Just a thought.

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    Hudo
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    Thanks all, I should further clarify that setting it on Max was the baseline, as reducing it down to min just slows the pellet further across the board. Max measured speed has been 900FPS at around 100 Bar on max- dropping it to 5 on the wheel is resulting in 890fps. Rifle is brand new impact x fired around 250-300 pellets. Ive read about increasing pressure doesn't correlate to increased speed and the opposite can be the end result hence my question about the gauge, what sort of max speed should i be looking for with 18gr Jsb heavies? As i may just leave it where its currently at and wait for a new gauge. 

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    Bob_O
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    100bar seems low to get 900fps from an 18gr pellet.  Maybe your gauge IS off/not reading accurately.

    I know it's not the same gun, but my Crown 22 would no way get anywhere near that velocity at 100bar, or even 120bar.  It thinks about it at 125bar though.

    Right now I have my reg set at 140bar, power wheel on 25/30cal, hammer spring adjuster on 5 with maximum compression.

    I get 927fps average with the JSB 18gr. 500mm barrel.

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    BDX
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    Bob_O

    Right now I have my reg set at 140bar, power wheel on 25/30cal, hammer spring adjuster on 5 with maximum compression.

    I get 927fps average with the JSB 18gr. 500mm barrel.

     

    Bob, could you clarify…"5 with maximum compression". I get that its 5 on the PW but the "maximum compression" throws me…

     

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    Bob_O
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    Max pre-tension on the slider adjustment screw.

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    Hudo
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    Thanks All, Im now looking into the hammer spring tension as a possibility- 

    AOA has listed stock settings for all cals and it lists 18.5mm as the .22 setting. 

    Mine is 21mm…. could this explain too soft a spring tension results. whats the verdict wind it up to 18.5 or any other better suggestions?

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    Hudo
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    another thought – could be someone _ (dealer) has swapped out a 177 for a 22 barrel as it is awfully close to the 20mm preset tension and reg settings etc etc for a 177.

     

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    OrdnasNS
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    On the case should be factory sticker with model, serial number and caliber of a gun so check it. On MAX for HST, 21mm is a very weak tension, dial it wit hex key on around 18mm and do the chrony work again.

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    Hudo
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    tightened it up to 18.5mm – 100 bar is now producing 930fps on max

    – about 110 bar (ish) saw it at 980fps. 

    now im confused as i though it would have dropped the FPS as it allows less air through with a tighter hammer spring..? and I would need to crank up more reg pressure to bring it back up. 

    other things to note is the fps is sometimes appears to be varying around on the same setting ( varying around 20fps) 

    then on other power settings its really uniform. 

    Should I be paying off the manometer reading and waiting for a new one ? or fine tuning the hammer spring . im not chasing max speed just best accuracy. 

    using the generally accepted speed of around 900fps as a start point.

    Thanks so far to everyone pitching in on this – its been a learning / scratching the head experience

     

     

     

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    ackuric
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    Glad you're getting to the bottom of your problem..hammer spring / energy was part of the issue. 930 fps @ 100 bar is quite high…gauge is likely off? 100bar = 1450 psi, if I do the math that I do so well, I get 864 FPS as your peak…provided 500 mm barrel that most .22 cal have…to get 930 fps I need to put pressure up to 115 bar. Now if you have a 600 mm barrel then…I get 100 bar making roughly 930 fps and your gauge is fine…so that information should help pertaining to gauge accuracy…at least IMO

     

    GL

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    Bob_O
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    Math is one thing, actual results are another.

    Good luck getting an 18gr 22 caliber pellet going 930fps out of a 500mm barrel at 115bar.

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    ackuric
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    Bob_O

    Math is one thing, actual results are another.

    Good luck getting an 18gr 22 caliber pellet going 930fps out of a 500mm barrel at 115bar.

    I have…you wanna know more details or just assume? Tell me more about how I am wrong…this is 90% bore porting, proper plenum size, 1650 psi and 19.5 barrel…and yes its been done and will be again, and again, and…

     

    What happens if I take away the proper plenum from the above? Tried, tested, and mathematically modeled, 913 fps @ 18 cc plenum, @ 891 fps for 15 cc's plenum, 831 fps fro 10 cc plenum, oh wow look at all those fps just go right away with smaller plenums..

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    Bob_O
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    You admittedly have zero hands-on experience with FX airguns.  Yet you insist that the calculations you make, based upon generic parameters, apply to this FX model the same as they apply to whatever brand you have experience with, or for all models across the board.

    The advice I gave was based upon my actual results with a similar rifle, which is far more accurate than the calculations you insist are correct in thread after thread dealing with rifles you have no experience with.

     

     

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    Hudo
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    not sure about plenums… or the math/science but my 600mm .22 barrel is spitting them out bloody fast with 100bar of pressure hey…

    Thanks everyone for the heads up- learn new things everyday…

    anyone got some scoop on about how fast to push this sucker to get the best out of it?

     

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    Hudo
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    So I've been playing with the hammer spring tension- so far ive worked out it is increasing the speed of the pellet when set at 100bar ( .22 18gr is now pulling around 910fps / 100bar /18mm HST – 600mm x barrel 

    What i appear to be noticing is the speeds seem to be a bit more uniform when more tension is being applied on the hammer. ive still got a fair bit of gap there (3mm or so ) before it maxes out. I haven't had time to start increasing pressure here but it would seem from the last run it will significantly increase. 

    Im not chasing speed but accuracy so i guess all i can do is keep playing , however does anyone have any scoop on winding out the HST to max?  ( Earnest does it in 1 video)  Pros/Cons

     

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    Bob_O
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    Sorry, I forget that the Impact 22 has a 600mm barrel vs. the Crown 22 at 500mm.

    You only need to do that if you're tuning for more power. 

    If you're getting the velocity you want at whatever reg pressure you're running without being on MAX hammer wheel position, you don't need to adjust for more tension.

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