Legal fps for ft.

Discussion in 'General Airgun Chat' started by springer34, Apr 16, 2013.

  1. springer34

    springer34 anschutz 9003

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    Just a quick question ive changed from jsb 8.4 to jsb heavy 10.34 what is the legal limit allowed for ft. at the moment my rifle is between 706 fps to 710fps is this ok or should i turn the power down?
     
  2. Conor

    Conor Never been banned from sales Staff Member

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    ok......I think:confused:
     
  3. mykeed20

    mykeed20 Member

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    Last edited: Apr 16, 2013
  4. RobF

    RobF Administrator Staff Member

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    10.34 gn is 722 fps at 12ft-lb (does vary depending on what constant the calculator uses), so the BFTA limit is 12ft-lb minus 5 fps, so that gives you a top of 717 fps. Your close, but not over.
     
  5. maestro

    maestro European Champion 2018

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    The theoretical limit is 718 but JSB Heavies are only 10.3 grains in reality so 719 is the real BFTA limit. 706-710 is not bad, but I use my rifle on 700-705, it is safer and a few fps don't really count.
     
  6. AIRFIX GILLY

    AIRFIX GILLY WFTA World Champion 2012

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    cylinder exchange

    Hey up Andras,
    As im a bit thick about these things and whilst were on about velocity with heavy pellets does shooting these pellets use more air?? As i have noticed you have to exchange your cylinder half way around a gp coarse.
    If you switched to 8.4 grain pellets would you still have to do this?
    Gilly.
     
  7. springer34

    springer34 anschutz 9003

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    ty for posts i think ill go the safe route and try to get it down a few fps just for the hot weather if we get any:rolleyes:
     
  8. fireblade

    fireblade Team AirArms

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    to find out how many shots you can get just fire it over a crono till you know?.
    :D:D:D:D:D:D:D:D:D:D:D:D:D:D:D:D:D:D:D:D:D:D:D:D:D:D:D:D:D:D:D:D:D:D:D:D:D:D
     
  9. maestro

    maestro European Champion 2018

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    No problem Gilly, I know that some have their special theories but I have never changed cylinder halfway of a course, it is not needed because my rifle can do 90-100 shots with a fill. I used to carry my spare cylinder around when my wife takes the car for some sightseeing and I stay there all the day.
    Anyway you surely know how PCP rifles work, they use air more effectively with heavier pellets so if I switched to lighter ones then I had to set the rifle's power a bit higher to have the same output power, i.e. the rifle would use more air.
    Air consumption has nothing to do with velocity, I can set a Feinwerkbau on a way that it can give even 230 shots, the problem is that there is a 30 fps deviation in them. So I used to set it other way which uses more air but only 3-4 fps deviation in velocity.
     
  10. springer34

    springer34 anschutz 9003

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    Now that's what I call a answer I have a p70 think I'll be bending ur ear regarding set up and such issues
     

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