Advanced Marksmanship Wind value calculations
- Thread starter Ryguy
- Start date
OP your post doesn't make sense on numerous levels, and your math is wrong in both of your posts, thus the jeering.
If the firing line is 0 degrees then factor equals COSINE of the angle created by the wind and the firing line. If you designate 0 degrees as the line from you to the target then take the SINE of the angle.
Or Google wind shooting diagram for more of a visual aid. Simple trig dictates that most wind calls are made off of the 30, 45, and 60 degree angles. COS (75) does give 1/4 value so its handy too. ELR would require more precision.
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If the firing line is 0 degrees then factor equals COSINE of the angle created by the wind and the firing line. If you designate 0 degrees as the line from you to the target then take the SINE of the angle.
Or Google wind shooting diagram for more of a visual aid. Simple trig dictates that most wind calls are made off of the 30, 45, and 60 degree angles. COS (75) does give 1/4 value so its handy too. ELR would require more precision.
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Right, sin(45 degree) = .707 and sin(25 degree) = .4226. Which is why a 90 degree wind in relation to bullet path is calculated at the full value of the correction thus, sin(90 degree) = 1. Say, a 10 inch correction at 500 yards for full value wind but with ¾ value wind (45 degrees), 10(.707) = 7.07 inch correction. Again, a 10 inch correction x sin(90) = 10, or the full value of the correction. Knowing the wind direction in degree rather than the o'clock method seems more precise and when shooting past 1000 yards becomes necessary. Also, You seem to be educated in trigonometry so you understand that sin(45) and sin(135) are the same thing which makes my point that .707 and .4226 are correct in relation to ¾ and ¼ wind corrections. How can you say my math is wrong when even cos(45) is still .707 and yet cos(90) = 0, therefore for correction values, which is what we do in shooting, your math is wrong. I can also explain that, but it requires basic calculus. To set a function of corrections or (limits) to zero as you stated with Cosine, which does not make sense, we can set f(x) = (x-1)/(x-1) which is undefined because although basic algebra says that it would be 1, it is actually undefined and unworkable since nothing can be divided by zero. A 90 degree wind correction of 10 inches dived by 0 for no value correction is UNDEFINED!!!!. Yet with sine, which is y/r, sin(90) = 1, a 10 inch correction x 1 still equals 10. I understand setting 0 and 180 as the firing line which gives cos(90) = 1 for a full value wind but when is that last time you heard someone say, "We have a full 0 degree wind.." We can get into statistics next if you like.
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From an earlier thread: http://www.snipershide.com/shooting...s-all-stop-doing-wrong-wind-call-verbage.html
I created the follwoing diagram.
I created the follwoing diagram.
^this.
No need to over think it. i treat all my 1/2 value wind calls as just that, half. I take whatever my full value adjustment would be and devide it in half.
Saying Half value is wrong, it's half the distance, not half the call...
This is a better representation of how your calls should be adjusted based on angle to the shot
This is a better representation of how your calls should be adjusted based on angle to the shot
I'll trust you got the math right because I'm too lazy to check, but the above quote is where you're getting off track. You can't estimate wind direction with that amount of precision, and wind isn't constant over 1000 yards anyhow.
It's the whole, I'll be more precise where it doesn't matter and hope that fixes all my other errors.
As noted, wind is not constant by any stretch of the imagination, so all we can hope to do is break it somewhere in the middle of all the variations caused by wind.
As noted, wind is not constant by any stretch of the imagination, so all we can hope to do is break it somewhere in the middle of all the variations caused by wind.
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