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Thread: 200yards

  1. #46
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    Quote Originally Posted by Merchant View Post
    Actually, you might be...

    Speed of sound in air is only linked to temperature. Speed of sound in other mediums is a whole load more complicated!
    From that you could say that no matter how far from target the trajectory would remain the same

    Gary is pretty clued up on this subject but I admit I aint
    Baz
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  2. #47
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    Quote Originally Posted by Gary C View Post
    Interesting but superficial. Just because the author of this piece says ignore altitude doesn't mean he is literally correct. You ignore altitude because you are using Rho, air pressure. The reason that altitude has an effect is because of the change it has on Rho. If you have already measure Rho then the altitude that Rho is measured at is irrelevent.

    If you don't have Rho, and are making a calculation, then you will need the altitude to be able to make it.

    http://en.wikipedia.org/wiki/Density_of_air
    Sorry, I still don't agree. I can't find any reference to pressure or density (P) being relevant to the speed of sound in air. During my training, I remember being specifically taught that is was purely dependant on temperature.
    This page sums it all up quite nicely.

  3. #48
    Gary C Guest
    Merchant.

    My congratulations on a well reasoned argument , and I concede happily. My training as a surveyor was 30 years ago time has let me remember some points but let me forget others.

    SoS varies with altitude, that is a simple fact.
    SoS varies with pressure and density, that is a fact.

    However I forgot that the relationship between pressure and density is opposite and equal, therefore as one effects the S0S with altitude the other cancels it out. Therefore, as you said, these factors do not come into play.

    However the original assertion with I remember well is that SoS varies with altitude is correct due to temperature and humidity calculations. In Europe, IIRC, temp declines 3 degrees per 1000 feet and humidity changes also. This means that, in theory, given constant humidity and temp S0S will remain constant with altitude, while in practice I know of no geographical region where there phenomena could occur

    Many thanks, I've enjoyed re-reading this and it's brought back some memories. My thirst for knowledge quenched, I'm off to surf for porn
    Last edited by Gary C; 05-06-2008 at 03:09 PM.

  4. #49
    verminhunter is offline The founder of the FAC .25 Big Boys Fan club
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    Quote Originally Posted by Gary C View Post
    I'm off to surf for porn





    And Bash the Bishop too .

  5. #50
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    seen this clip. would an owner of a fire arms certificate make such a clip?
    Looks a bit odd to me.
    THE DEER HUNTER
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  6. #51
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    Quote Originally Posted by r.j.s. View Post
    seen this clip. would an owner of a fire arms certificate make such a clip?
    The shooter is not from the UK - his youtube profile says he's Polish.

    I don't know about Polish airgun law, but I would suffice to say, it is not the same as UK law. It is entirely possible, although I cannot say, that like in the US, airguns of any power are exempt.

  7. #52
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    It looks like it is around 200m to me!??
    If he was running 950'ish....with a heavy'ish lead...it looks about right to me!

    I froze the frame and had a good look it appears to be twice as far as i have ever shot!

    bit stupid with the glass but good shooting!..I wonder how many shots it took though?..Most likely cut the vid.
    I love this long range stuff!...Can't wait to have a go myself when i get a chance!
    Interesting!
    SIHFT Winners 2011 - 2012 - 2013 - AND 2014....2015..2016...oh look back at green...running out of colours! Ha!

  8. #53
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    He aint going to get 950fps with heavy lead, not in a S410E, Bismags will not reach 950 unless gun has been modified and the sound of the gun sounds std FAC

    I have shot air rifles up to 100ftlb plus, and that is a 28-30ftlb AA with Exacts

    I still think its 100m made to look 200m easy to do if you zoom in and out with cheap camera
    Baz
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  9. #54
    Gary C Guest
    Quote Originally Posted by Skoll View Post
    The shooter is not from the UK - his youtube profile says he's Polish.

    I don't know about Polish airgun law, but I would suffice to say, it is not the same as UK law. It is entirely possible, although I cannot say, that like in the US, airguns of any power are exempt.
    No they are not

  10. #55
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    Quote Originally Posted by Gary C View Post
    No they are not
    Well, fair enough - I've never seen fit to study Polish gun law, so would you care to elaborate for the benefit of those of us in the dark about it?

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