Bucking the wind better BC or weight ?

Discussion in 'Rifles, Bullets, Barrels & Ballistics' started by trader388, Oct 16, 2004.

  1. trader388

    trader388 Well-Known Member

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    What is more important when it comes to bucking the wind. The higher BC or the weight of the bullet?

    180berger vld .698bc shot at 3000fps
    &
    210berger vld .640bc shot at 3000fps

    The numbers say the lighter weight higher BC bullet will have less wind drift. But some say in real life the wind will affect the heavier bullet less.
     
  2. Michael Eichele

    Michael Eichele Well-Known Member

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    It depends on several things, but for the most part the higher BC will perform best in wind. A 200 grain round nose flat base will never dope the wind as well as a 155 match bullet fired at the same velocity in the same apmoshere.
     
  3. Ray Meketa

    Ray Meketa Well-Known Member

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    trader - The higher BC will always win. Accepting this fact seems to be one of the hardest things for shooters to do. It may not seem right but it is. You can't fool mother nature. In the days before chronographs and PCs it was easy to argue the opposite, and win the arguement. But not anymore.
     
  4. Varmint Hunter

    Varmint Hunter Well-Known Member

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    And one other thing - The 180gr bullet could easily be fired at greater speed with the pressure remaining the same as the heavier bullet at a lower velocity. Higher BC AND a higher muzzle velocity is a home run in windy conditions.

    Given similar bullet shapes, a heavier bullet normally also has a higher BC but can be driven at a lower velocity. Thats the trade off.

    [ 10-16-2004: Message edited by: Varmint Hunter ]
     
  5. Dave King

    Dave King Well-Known Member

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    Trader388

    A bullet is effected by the intensity and duration of the wind. We can't change the intensity but we can change the duration and the way to do that is decrease the exposure time. Less exposure equals less deflection.

    Shoot the bullet that travels the distance in the least amount of time.
     
  6. trader388

    trader388 Well-Known Member

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    Okay...what would you rather hit a deer with at 1000 yards?

    A 7mm diameter 180gr bullet with -218 inches of drop, 1366 ftlbs of energy, and 75 inches of windage, and time of flight 1.25 sec.
    or
    A 30cal diameter 210gr bullet with -246 inches of drop, 1322 ftlbs of energy, and 88 inches of windage, and Time of flight 1.35 sec.
     
  7. Guest

    Guest Guest

    The one that hits where you point it..
     
  8. trader388

    trader388 Well-Known Member

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    That's a given.
     
  9. James Jones

    James Jones Well-Known Member

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    It seems that the 7mm 180gr bullet would be the one to use , more energy , less drift and drop and probably less recoil.

    Was their realy a quiestion here or were you just pointing out to use 30 cal guys that the 7mm is a better choice?

    The 7mm and .264 deffinatly have the better BC bullets for the long range shooting but I still love the 30's
     
  10. trader388

    trader388 Well-Known Member

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    Oh just trying to decide between a 7wsm and 300win mag. Then there is always the 300rum...but if I am going to burn that much powder I'd rather burn it to push a 300smk out of a 338lapua.
    [​IMG]

    But the question is can you get 3000 from a 300win 210berger combo or 3000 from a 7wsm 180 berger combo... 27" rock or schneider barrel on each.

    [ 10-16-2004: Message edited by: trader388 ]
     
  11. Varmint Hunter

    Varmint Hunter Well-Known Member

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    Try a compromise cartridge - 7mmRUM [​IMG]
     
  12. trader388

    trader388 Well-Known Member

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    7rum - case is too tall to fit anything into the mag while seating out the bullets.
     
  13. Len Backus

    Len Backus Administrator Staff Member

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    I think the issue of having to seat the bullet farther than normal into the case is much over-rated. The issue is one of lost case capacity but if you actually do a calculation, nothing significant is lost.
     
  14. RBrowning

    RBrowning Well-Known Member

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    Well, color me stupid! I thought that BC was a function of the shape of the bullet and it's effect on drag and how quickly the bullet slows down along it's axis of travel. The weight is a function of it's volumn and the density of the material it is made of.

    Given two bullets with the exact same shape, one made of lead and one of copper, would they not have the same BC?

    If fired at the same velocity, not pressure, would they not drift the same?

    If loaded to the same pressure, would the copper bullet not travel faster because it accelerated quicker? Would this not lead to less drift?

    If you made another two bullets, one out of lead and one out of copper, that had the same ogive and boat tail, and weighed the same, wouldn't the copper bullet be longer and have a heigher BC?

    Dazed and confussed?!?
    Rick
    [​IMG]

    -edited for misssssspelling

    [ 10-17-2004: Message edited by: RBrowning ]