Wind Question - Need help please

BeteNoire

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Apr 2, 2009
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I have a wind question that has been irritating me at my regular shooting area. We consistently get 5-10 mph winds from 3 different directions at one of the targets: a 5 o’clock wind for the 1st third of the bullet flight, 7 o’clock for the 2nd third and close to 9 o’clock for the last third.

I recently watched Emil Praslick's recent online wind class where he discussed the relative contributions of winds broken into thirds, but he didn’t give a specific example on how to adjust wind deflection dope when the direction changes drastically.

The picture I attached is for a target at 1200m. Regarding winds from opposite directions: If the wind influence over the final third of the flight path only contributes 10-12 percent of the overall wind influence (per Emil's wind class), would I take 10% of the last thirds deflection dope (adjusted for cosine) and subtract it from the aggregate from the first 2/3 dope?

Hopefully that description makes sense. I cannot wrap my head around the math here and the Kestrel doesn't let you divide up a flight path that way.

wind question.jpg
 
Your just gonna have to measure the wind at the shooter. Take a shot and adjust. The 1st shot wind call comes with experience. Experience equals missing a lot

I would hold middle left with the dope for wind at shooter.
 
This is a shot in the dark and something I will try next time I am out. You could try it too and see if it works.
(All Theory)
make a wind call for each of the section and thier respective yardages
sector 1 = 400yds - wind call is 0.8right for that first sector
sector 2 = 400-800 - wind call is 0.4 left for that 400yds
sector 3 = 800-1200 - wind call is 0.8 left for that sector.

According to Dan Perriard's article (attached) from the Invisti site the first 1/3 of the distance is 45% of the wind call, the 3 nd 1/3rd is 35% of the wind call and the last 1/3 is the remaining 20%

now take your wind holds from above and multiply them by the sector values (x10) above.
sector 1 = 0.8x4.5 sectors = 3.6 right
sector 2 = 0.4x3.5 sectors = 1.4 left
sector 3 = 0.8x2.0 sector = 1.6 left
total = 0.6 right. (is this close)

we may need to adjust the sector factors to get this right. and as Dan shows in his article the total distance to the target makes a difference in how much each sector makes a difference.

Try it. The only thing you have to loose is a bullet (powder, primer). This would be the science part that we can work to refine.
 

Attachments

  • Where Does the Wind Matter - Dam Periard.pdf
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