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Altitude and pattern density

Discussion in 'Shooting Related Threads' started by MtnGun, Jul 5, 2011.

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  1. MtnGun

    MtnGun Member

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    Does altitude effect how tight a pattern is? Does a shell/choke combination shoot tighter at high altitude or at lower?
     
  2. twotimer

    twotimer Member

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    MtnGun, I would think it would affect it somewhat. If you shot in a vaccum, the shot would never spread out without the resistance of the air. That is a good question though. If you are shooting a mile or so above sea level, do you use a more open choke? I used to play golf in Park City Utah, and that was almost a two club difference with less air resistance. Mike
     
  3. Pull & Mark

    Pull & Mark Well-Known Member

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    In a word "don'tworryaboutit". This new question should be pretty good. I think I'll make some popcorn and sit back and watch!!! Break-em all. Jeff
     
  4. gyrine

    gyrine TS Member

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    I'm curious too. I shoot at above 6000 feet most of the year and at below sea level in the winter. I don't notice a difference but that means zip. Rich
     
  5. Trapboy1957

    Trapboy1957 TS Member

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    Phil Kiner should know. Hey Phil??? Jr
     
  6. ivanhoe

    ivanhoe Well-Known Member

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    Pattern your gun at both altitudes and see if there is any difference!!!!

    Bob Lawless
     
  7. School Teacher

    School Teacher Well-Known Member

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    Is not the key variable the density of the air? The higher you are above sea level, the less dense the air, all other variables being equal. However, a key variable is the relative humidity. I would conjecture that at low elevation and low humidity, the air density may be less than the air density at higher humidity and higher altitude.

    All in all, I don't think that altitude will make that much difference.

    The air density probably has more effect on target speed than shot speed as targets are larger and less dense than shot.

    Ed Ward
     
  8. V10

    V10 Well-Known Member

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    Humid air is less dense than dry air.
     
  9. School Teacher

    School Teacher Well-Known Member

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    My bad ...

    Humid air is less dense than dry air because a molecule of water (M ˜ 18 u ) is less massive than either a molecule of nitrogen (M ˜ 28) or a molecule of oxygen (M ˜ 32). About 78% of the molecules in dry air are nitrogen (N2). Another 21% of the molecules in dry air are oxygen (O2). The final 1% of dry air is a mixture of other gases. (From the Wikipedia)

    Still, air density will have an effect on the speed of targets and shot.

    I should have conjectured that as elevation increases, air becomes less dense and that as humidity decreases air becomes less dense. Low elevation and low humidity air is more dense than higher elevation and higher humidity air.

    Did anybody mention temperature or wind velocity? Elevation alone is but one of several factors that affect target or shot speed.

    Maybe it’s best to forget everything and just break the target.

    Ed Ward
     
  10. Neil Winston

    Neil Winston Well-Known Member

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    I've patterned two guns at 40 yards at each of Spanish Fork and Cheyenne. Patterns are way, way tighter at both those high elevations than at the 1000 feet I do most of my patterning at. Of course I have all the data, all the pellet-count numbers, and even a few assertions about what it means.

    I'll get it on Claytargettesting.com anon.

    Neil
     
  11. RV4driver

    RV4driver TS Member

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    The important thing to remember is that the shot doesn't know, and the bird doesn't know, the gun/choke, etc. doesn't know...but YOU know, and that will weigh on your mind, affecting sleep, eating and drinking habits. But mostly, when you mount the gun and call pull, you'll be thinking about it, and...LOST! But maybe that's just me.

    Jeff
     
  12. 1oldtimer

    1oldtimer TS Member

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    When Dale Amos of Utah averaged .9827 on 2,200 targets from the 27 yard line in 1992. I think he only missed about 38 targets. Did the altitude play a part? I think most of his targets were shot at Spanish Fork? Clyde
     
  13. Neil Winston

    Neil Winston Well-Known Member

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    Altitude certainly played a part, Clyde, but Dale's amazing ability to break long-yardage targets was the main determinant for sure. All Dale did was reduce the chances that he would lose a bird on which he had done everything right. And to post scores like that you have to do everything right all the time.

    It is my view that, in the Midwest, at Sparta, Vandalia, and the Cardinal Center, shotguns are about at the limit of their ability to break them all from the 27 and that's if you shoot quite fast. At high altitude, that limit is found farther back and so the odds of a loss when the bird is perfectly pointed is reduced. Or, alternatively, you have a bit more time to make the shot you want to.

    Neil
     
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