Quiet is as quiet sounds

Forums General Discussion Quiet is as quiet sounds

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    spinj
    Participant
    Member

    For some time now my 8 FPE Cricket with Donny’s first-generation carbon fiber shroud and LDC combo has been serving me so well in terms of backyard pest control and target shooting I feel no need to raise the power.   It’s got all the energy I need to eliminate pest pigeons up to 30 yards.  But the best part, aside from the 430 shots I get (with a 10-13 extreme spread), is the stealthiness of the shot report; it’s so quiet I can hear the pellet whizzing towards targets to 27 yards!  Amazing.  Anyway, just wanted to share.

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    Mick-VA
    Participant
    Member

    That sounds fun!  Talk about shot count.  Is that in .22 or .177?  What pellet do you use to match up 8fpe?

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    spinj
    Participant
    Member

    Mick, My Cricket is in .22 caliber.  The energy level is achieved using JSB Exact Express pellets (14.3 grain) at 525 FPS.  The fill working pressure is from 220 – 40 BAR using the gun’s air gauge.  Using my SCBA tank’s gauge, it would be 230 – 50 BAR, which I think is the more accurate pressure range.

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    sirk
    Spectator
    Spectator

    how did you prevent hammer bounce at low regulator output?

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    sirk
    Spectator
    Spectator

    you must be one of the few guys here who can tune airguns properly in wide range of fps output.

    typically all the tuning on US forums is basically trying to max out fps and break the guns mechanics 😂

    well done. 

    i suggest you do a separate tuning thread 👍

     

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    spinj
    Participant
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    Sirk, I actually shared my tuning tips here a while back.  I’ll see if I can find the post and share it again.

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    spinj
    Participant
    Member

    Sirk, here are the tuning tips I shared (the italicized passages below).  I copied it from the post I made as a response to someone’s query in the past.

    The key to getting the maximum amount of shots first starts with deciding on a power level that is lower than maximum yet sufficient enough to satisfy your shooting needs.  Then it’s a matter of adjusting your regulator’s output to the point in which you are able to shoot at your desired velocity/pellet energy level.  If your valve spring tension is adjustable (like on guns like the Cricket or Vulcan) start with a medium to tight (compression) setting, while keeping in mind that too much tension results in valve lock and too little results in the likelihood of the tank dumping all the air out due to its inability to seal it in.  There is a happy medium to be reached here.  You should also start with the tension of the hammer spring high as well.  If the velocity is above that which you’ve decided on, decrease the tension on the spring.  If, in such a case, you’ve backed out the adjustment of your hammer spring knob all the way and are still getting high velocities, you will need to use a lower power spring.  Once you’ve reached your target (no pun intended) velocity keep backing out the adjustment knob to further decrease spring tension while still being able to retain the desired velocity.

    Now here’s the not-so-tricky part.  Your goal should be to have a setup that, when the regulator falls below its end-working pressure, the remaining charge in the air tube (unregulated air) allows for a consistent power curve and that the hammer and valve spring tension is tuned to work harmoniously with it to still produce consistent shots.  Remember, at this point the regulator piston will no longer close and seal off the unregulated air.  For clarification, think of an unregulated PCP that is being shot within the sweet spot of its curve.  You want to make sure that the shots coming from this current state of the air reservoir is able to give you the remaining “unregulated” but consistent shots and not those that exhibit a sharp velocity spike, which often results when the hammer and valve spring tension is incorrect.  This is the primary reason why I say that it is necessary to tune/adjust the hammer and valve spring in addition to adjusting the regulator. 

    Quite simply, the spring rate of both the hammer and valve spring must be tuned/adjusted properly (with the valve spring tension to be as little as possible) while still being able to let the gun deliver consistent velocities during its regulated state and also when it comes into its unregulated state.  Adding onto the increased number of shots from a well-tuned system, it is also the extra amount of shots yielded from the unregulated state that basically contributes to an even higher number of overall shots.

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