Temp vs Velocity- insights and solutions

Discussion in 'Long Range Hunting & Shooting' started by fatrack, Sep 18, 2010.

  1. fatrack

    fatrack Well-Known Member

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    Dec 8, 2009
    I'm burning US 869 because it is supposed to be temperature insensitive and I just got a serious wake up call! I went from 9.25MOA of come up for 556 yard shot at 75F to 11MOA at the same distance at 32F. (shooting 300 SMKS w/99grains US869 in a RUM)

    Do you guys try to keep your shells warm when your out glassing for game in cold weather or do you figure out your come ups based on temperature of the shells? I run Exbal and was wondering if there was anything about this program concerning temperature I should know about?

    I live in Alberta so temps get pretty extreme here!
     
  2. loosesniper2000

    loosesniper2000 Well-Known Member

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    286
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    Jun 25, 2009
    The temp makes a huge difference! If you want to be precise with your shot placement you'll have to adjust to the given temperature. That's why a hand held unit is nice. If you don't have one the next best thing is, have a couple different click charts based on the variance in temperature.

    I used to "bake" loads when I competed in long distance, not only is this unsafe but unreliable. I lost a shoot one time in Heavy gun 1000 yard comp because the sun peeked behind the clouds on my 10 shot and it dropped about 8-10 inches low.
    The weather is the biggest factor when shooting long distance so my best recommendation is carry different charts based on 10 degree increments

    Hope this helps
     

  3. Rocky Mountain

    Rocky Mountain Well-Known Member

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    Sep 13, 2010
    I tried US869 in a big 338 and gave up on it in the end, yes it shot great at long range but the vetocity range was way to big in different temperatures on different months of the year giving different impact points on the target at 1000 yards++. There are to many other things to worry about at long range,