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Thread: fps Variance with altitude

  1. #1
    MCJ
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    Default fps Variance with altitude

    Has anyone got an idea of how the pellet speed vary from say Cape Town which is at sea level to Pretoria which is roughly 1350 meters above sea level. Facts please. iow
    Someone who has done shoots at both altitudes and used the same chrony,
    the same pellet weight i.e. 8.4gr,
    charged the rifle to the same pressure,
    etc
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  2. #2
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    I lost approx 20 fps in the Worlds. It wasnt so much the loss of speed as the air density that affected things. I had to completely re-adjust my settings to compensate, not pleasant when your used to high altitude shooting and suddenly find you can see the pellets falling to the ground.
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  3. #3
    MCJ
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    Urabus, what do you find going from Durban to shoot in JHB and Pretoria area.

    Is there any other guys that can elaborate on this issue?
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  4. #4
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    it's all in the mind ???? ..............the one time i reckon there's a difference, i spent 2 sessions zeroing the scope (out by 14 clicks @ 50m) and i ended up missing most of the reduced and long range targets. maybe the EV was still settling in???????

    since then, when ever i go up to shoot, i merely check the zero and shoot as it is. i still miss them the reduced and long range shots..........but now i get a few too

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  5. #5
    MCJ
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    Thanks for the feedback.
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