Extreme altitude effect on wind correction- can anyone confirm?

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Jul 17, 2013
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567
Getting ready for a hunting trip that will be at high elevation (15,000+ feet). Living at sea level, all of my most of my practice will be at basically sea level. I am very aware of altitudes effect on bullet drop. But crunching the numbers on the wind correction it gets kinda odd.

According to applied ballistics and the berger ballistics calculator, the windage correction for the SAME SPEED wind is roughly 1/2 at 15,000 feet vs sea level. Can anyone confirm this is correct?

To elaborate, my gun number is 7mph at sea level. So at 500 yards, a 7 mph cross wind will require a 0.5mil correction. At 15,000 feet, the same 7mph wind requires a 0.25 mil correction.
 

Formidilosus

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Oct 22, 2014
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Getting ready for a hunting trip that will be at high elevation (15,000+ feet). Living at sea level, all of my most of my practice will be at basically sea level. I am very aware of altitudes effect on bullet drop. But crunching the numbers on the wind correction it gets kinda odd.

According to applied ballistics and the berger ballistics calculator, the windage correction for the SAME SPEED wind is roughly 1/2 at 15,000 feet vs sea level. Can anyone confirm this is correct?

To elaborate, my gun number is 7mph at sea level. So at 500 yards, a 7 mph cross wind will require a 0.5mil correction. At 15,000 feet, the same 7mph wind requires a 0.25 mil correction.


Yes, change the wind bracket based on density altitude.

For the 6XC I am using right now-

At 0ft DA it’s a 6mph gun-
DF6EF8E3-FA0F-4CA5-889C-F7B27983B808.png



At 15,000ft DA it’s a 10mph gun-

33BD0145-FDB4-46FF-88D4-5CEC4FFE03A3.png
 
OP
Cactus kid
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Jul 17, 2013
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567
Thanks for the verification. I would have lost money on that bet!
 

Shraggs

WKR
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Jan 24, 2014
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Zeeland, MI
Yes, change the wind bracket based on density altitude.

For the 6XC I am using right now-

At 0ft DA it’s a 6mph gun-
View attachment 460573



At 15,000ft DA it’s a 10mph gun-

View attachment 460574
Form, 2 questions if I may.

How do you know - or what’s the formula/criteria for modifying wind bracket according to da? Ie, what is a 4 or 5 mph load going to be at X da? It must vary with increasing da correct?

Second why not an adjustment factor in mil or moa for increasing da? Is this more efficient? I’ve played with different da on a 4 mph load and it seems that every 4000 change in da reduce hold by .1 mil past 300 yards.
 

thinhorn_AK

"DADDY"
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Jul 2, 2016
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I’m taking a tikka 6.5 prc, 22” proof barrel, that lives in an XLR chassis. The optic is a NF 4-16x42 atacr
That’s awesome. Mountain hunting in Asia has always seemed like the pinnacle of hunting to me. I will hunt Marco Polo and blue sheep one day.
 
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