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Thread: How far will a pellet travel

  1. #16
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    Quote Originally Posted by timmaaah View Post
    Doesn't the heavier pellet retain more energy over distance? Must be something to do with inertia. That's my guess. Inertia.....or momentum....... no, inertia.
    Make yer flamin' mind up!

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  2. #17
    timmaaah is offline I'm starting to like my arse!
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    Quote Originally Posted by timmaaah View Post
    Doesn't the heavier pellet retain more energy over distance? Must be something to do with inertia. That's my guess. Inertia.....or momentum....... no, inertia.
    Quote Originally Posted by snock View Post
    Make yer flamin' mind up!

    Or is it kinetic energy.....





  3. #18
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    Quote Originally Posted by timmaaah View Post
    Or is it kinetic energy.....




    Ballistic coefficient.

    Gus
    The ox is slow, but the earth is patient.

  4. #19
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    Quote Originally Posted by timmaaah View Post
    Doesn't the heavier pellet retain more energy over distance? Must be something to do with inertia. That's my guess. Inertia.....or momentum....... no, inertia.
    Yup it does retain more energy (not a lot more though) when you get to .25 the max distance drops btw, but I cant remember what the terminal energy was now (lappy packed away again and I never got round to running chairgun under linux )

  5. #20
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    If you use the idea that the pellet is fired directly upwards then it will accelerate upwards slowing down until it stops, it will then fall. As it falls it will gain speed until it reaches terminal velocity. That is 9.81m/s/s. Force is mass multiplied by acceleration so the heavier the pellet the more force it has at terminal velocity (which would be the same).

    Why do we use big bullets for deer?

  6. #21
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    Quote Originally Posted by Gwylan View Post
    Ballistic coefficient.

    Gus
    Only that(BC) and muzzle velocity matters.
    Starting with the same velocity, the pellet with the better bc will go further.
    Shape and mass determines the bc.
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  7. #22
    tufty is offline I wondered how that worked..
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    I should have studied harder in school....I have no idea what any of you are talking about
    Steyr LG110 Hunter,AA410 in Gary Cane stock,HC, Steyr LP50,Morini 164ei,Morini CM84e,Anschutz 1417 thumbhole,Rimfire Magic 10/22,Anschutz 1913,Rieder and Lenz Z2,Keppeler 6mmbr

  8. #23
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    Quote Originally Posted by tufty View Post
    I should have studied harder in school....I have no idea what any of you are talking about
    Here, does this help?

    Quote Originally Posted by cambrai1917 View Post
    Maximum range achieved at an angle of 45 degrees . . .
    That would be true in a vacuum (no drag – infinite BC) . . . in the atmosphere though (especially with low BC, high-drag airgun pellets), the optimum angle is a lot less.

    Quote Originally Posted by dough View Post
    out of interest then, if you were to shoot vertically up, the pellet would eventually stop and fall down, so what would be its terminal velocity?!
    The free-fall terminal velocity is about 880 * sqrt(BC) Ft/s.
    0.177 JSB Exact Vt = ~ 880 * sqrt(0.021) = ~ 127 Ft/s.
    With the more manly calibre (0.22 JSB Exact say) Vt = 880 * sqrt(0.032) = ~ 157 Ft/s.

    Quote Originally Posted by dough View Post
    i mean i assume it would be the same as if you just dropped it fform a great height!?
    Correct since it is indeed being dropped from a, er, great height.

    Quote Originally Posted by dough View Post
    always pondered that one, but i dont get out much!
    Yeah, me too.

    Quote Originally Posted by Skipper View Post
    Somebody will correct me, but as to pellet size .22 will travel further than .177 as if you throw a squash ball and a ping pong ball the squash ball will go further.... does that make sense? lol
    Maximum range is a function of initial velocity and Ballistic Coefficient alone (and the ability to calculate the optimum angle of course). Calibre, mass and moon-phase are irrelevant.
    The quash ball has a much greater BC (than the ping pong ball) because of its vastly superior Sectional Density (since BC = Sectional Density/Form Factor and the Form Factor is the same for both balls) so would travel further at any non-zero angle and have a greater Terminal Velocity.

    Quote Originally Posted by Apache View Post
    If you use the idea that the pellet is fired directly upwards then it will accelerate upwards slowing down until it stops, it will then fall. As it falls it will gain speed until it reaches terminal velocity. That is 9.81m/s/s. Force is mass multiplied by acceleration so the heavier the pellet the more force it has at terminal velocity (which would be the same).
    At the top of the trajectory the projectile’s velocity is zero (relative to the ground). As it descends, it’s downward velocity increases driven by gravitational acceleration (~32.17 Ft/s^2 as you say). However, as the velocity increases it generates drag – proportional to velocity squared – the vector of which is acting against the gravitational acceleration. As the projectile’s downward velocity increases, the drag increases at an exponential rate until a limiting velocity is reached such that the drag force exactly equals the accelerating force (gravity). This equilibrium is reached at approx. 880 * sqrt(BC) [Ft/s] as above.

    Quote Originally Posted by Apache View Post
    Why do we use big bullets for deer?
    Big bullet = big mass = big kinetic energy . . . and big mass = big sectional density = big BC means that a bigger proportion of the initial KE and momentum are available at the target.

    In case you were wondering . . .

    Maximum_Range = 11000 * BC * Loge(MV / (880 * Sqrt(BC))) [Yard]

    Optimum_Angle = 45 * (1 - Exp(-((11000000 * BC / MV^2)) ^ 0.333)) [Degree]

    . . . believed to be the original work of Steve Woodward (Steve_in_NC)

    HTH
    Dave
    Last edited by Harry's Lad; 17-08-2010 at 09:39 PM. Reason: 880 not 800 . . . doh! . . . and added equations
    "Only two things are infinite, the universe and human stupidity, and I'm not sure about the former." Albert Einstein.

  9. #24
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    Quote Originally Posted by Harry's Lad View Post
    Here, does this help?
    I do love your posts Dave, they nearly always need reading properly with a calculator to understand

  10. #25
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    Quote Originally Posted by snock View Post
    Apart from it being dumb?

    If terminal velocity at 122mph were measured in fps it would be around 178fps.
    So, a 14.3gr pellet doing 178fps would contain just over 1.0 ftlb.

    Enough to blind you if you're looking up. That's why it's dumb.
    As kids, we used to fire vertically upwards regularly with the specific aim of having the pellet land somewhere near. That very rarely happened - and when it did, the best we could achieve usually involved us hearing the pellet land yards away. Dumb it may be - but not dumber than all the other dangerous things we used to do.
    Happy Shooting!! Paul.
    "We cannot solve our problems with the same thinking that we used when we created them" - Albert Einstein.

  11. #26
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    Tufty

    Hi Tufty.
    You and me both!
    When I die don't let my wife sell my guns for what she thinks I gave for them!!!

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