crosswind affects drop

Discussion in 'Long Range Hunting & Shooting' started by elkaholic, Aug 17, 2009.

  1. elkaholic

    elkaholic Well-Known Member

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    I was told by T.D.Smith (the guy who invented the Swarov TDS reticle) that a left to right crosswind (right hand twist) affects bullet drop by 1/4 of wind drift. (i.e. 40" drift=10" drop added) Anybody familiar with that?.....Rich
     
  2. phorwath

    phorwath Well-Known Member

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    First time I've ever heard or read of anything anywheres near that significant. Believe I've read there could be a slight horizontal cross-wind affect on drop, but so slight as to be ignored.

    I'll dismiss that rule of thumb until and unless I see further legitimate references which substantiate it.
     

  3. Michael Eichele

    Michael Eichele Well-Known Member

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    I am not actually 100% up to snuff on this subject. It is another issue I have been needing to research a bit further so take what is said here with a grain of salt.

    Here is what I do know. I know that the principal of what he stated to you is true. There is a verticle component with crosswinds and not just horozontal. I have bever been led to believe nor have I seen so much effect that it equalled 1/4 of the horozontal component.

    Maybe GG, 50, Carlock or Litz has a more educated answer on the subject.
     
  4. Boss Hoss

    Boss Hoss Well-Known Member

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    This will give all of you something to think about-----learn this and the wind will be your friend!



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    Last edited: Aug 18, 2009
  5. phorwath

    phorwath Well-Known Member

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    I've reviewed this chart and supportive narrative in the past and found it helpful. You may have even been the member that provided it in another Thread. But there's nothing here to suggest a significant crosswind-caused elevation rise or drop. Not one that can be calculated (pre-determined), let alone a 1:4 ratio of drop:crosswind.

    Wind = friend is perhaps overstatement? Less the enemy - yes. The knowledge is certainly a helpful aid.
     
  6. Boss Hoss

    Boss Hoss Well-Known Member

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    The bottom line is when competing at 1K if you do not know how to judge condition you do not win----fact plain and simple. Shooting at an anmial if you do not know how to judge condition at long range is nor responsible. People who struggle with the wind make it easier for me to beat them. Personally I hate shooting a match in calm or close to calm conditions.
     
    Last edited: Aug 18, 2009
  7. bwaites

    bwaites Well-Known Member

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    If crosswind causes a drop, then does bullet rotation cause a rise when it is into the wind?

    Where is Litz when you need him?:D

    Probably at Camp Perry!!

    Bill
     
  8. elkaholic

    elkaholic Well-Known Member

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    Knew this one would generate some discussion. I too thought that 1/4 drift sounded awfully high. Not sure if T.D. is still around, but if I remember correctly, he referenced a book called "The art of War" by John somebody? Also, as someone mentioned, it would then stand to reason that a right to left wind would lessen drop. It sure seems like if this were true, there would be a lot more out there in support. Otherwise, nobody would hit anything.......Rich
     
  9. 300ECHO

    300ECHO Active Member

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    in a right hand twist barrel with a left to right wind the bullet will climb down the wind slightly and in a right to left wind the bullet will climb up the wind but the effect is one eighth to one quarter minute of angle in??? 10ish mph wind not a quarter of drift value! shawn carlock mentioned this in one of the articles here on the LRH boards- hmm just searched its 2paragraphs up from the drawn diagram Reading The Wind
     
    Last edited: Aug 18, 2009
  10. phorwath

    phorwath Well-Known Member

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    So you were talking match competition. That was the furthest thing from my mind. When I'm hunting, the environmental elements are my competition, and the wind has never been my friend - ballistically speaking.

    The wind always wins if it gets knarly enough. I shot one brown bear in 70 mph cross-winds on Kodiak Island, with gusts exceeding 90 mph based on the wind meter mounted on a commercial fishing boat anchored back in a saltwater bay. The first shot missed, not because of bullet drift, but because of rifle drift. I was laying down, rifle rested on pack, and the wind gusts buffeted the rifle to the point that bullet drift was the least of my concerns. This wasn't long range - to avoid any ethics complaints. About 125 yds. It was tough enough to keep the rifle from being blown off the pack, let along draw a steady zero on the bear. Unfriendly conditions.

    The bear was oblivious to the wind. He had a hard time reacting to the first missed shot because the background wind noises made it difficult to determine if there was any unusual noise, let alone the source of it.
     
  11. 300ECHO

    300ECHO Active Member

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    elkaholic, phorwath, mike see my post above=)lightbulb
     
  12. elkaholic

    elkaholic Well-Known Member

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    I Read Shawns article which really helped. That makes a lot more sense to me than what I had previously heard. Thanks Echo......Rich
     
  13. phorwath

    phorwath Well-Known Member

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    Thanks for the reference to that post. I had previously read that article by Shawn, and articles by others also, that described the slight effect of crosswinds on verticle POI. I knew the affect was small enough to be disregarded, and I've never seen anyone attempt to mathematically model or predict it for practical application, even for the longest of long-range hunting shots. The effect is so slight that it would be lost in the background noise of all the other more significant parameters, parameters that can be predicted to help ensure first-shot hits on long-range targets.
     
  14. Boss Hoss

    Boss Hoss Well-Known Member

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    A 8 o'clock condition will put you at 2' o'clock. Very simple.