# Ballistics calculation

Discussion in 'Rifles, Bullets, Barrels & Ballistics' started by gregf, Dec 30, 2010.

1. ### gregfNew Member

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Dec 30, 2010
The ap on my phone ask for angle of wind i would like to know what this means and how to measure it thanks to anyone who can help

2. ### SBruceWell-Known Member

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Oct 31, 2009
Gotta be more specific. What kind of ap are ya runnin?

The programs I've dealt with for ballistics ask and compute for a direction relative to a 12 hour clock, with 12 being a wind straight toward you from the target. 3 and 9 are true 90 degree crosswinds, 6 is a true tailwind, blowing from you toward the target, ect.

Angle of wind can mean alot of things.............a true crosswind would normally be thought of as from 3 O'clock or 9 O'clock.........or 90 degrees relative to line of sight.

However, winds from different angles are where the confusion comes in.
I deal with angles and angles relative to other angles all day at work, lots of trigonometry in what I do. Heres what I am getting at.....

Example: A wind from 11 O'clock (30 degrees left of straight in your face) could be considered a 30 degree wind, or a 60 degree wind (60 degrees from a true crosswind) or a 330 degree wind (relative to azimuth, with 0 or 360 being true downrange), possibly even a negative or -30 degrees..............just depends on how the ap is configured for that input/calculation.

Perhaps if you give a little more info on what it is, and numbers you've put in, someone here will be able to tell you what particular input your app needs for an accurate solution.

Take Care

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633
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Mar 8, 2007
A common trend I've noticed (if not using the clock method) is to define a wind blowing in your face as 0 degrees, a wind from the right is 90 degrees, tail wind is 180, and a wind from left is 270 degrees.

Not sure this is the case in your app, but it's a common doctrine for ballistics apps.

-Bryan

4. ### LonerWell-Known Member

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599
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Apr 14, 2010
If that app is FTE you can choose wind dir. by the clock or by angle. I find the clock
to be easier. Go to Settings, FTE and scroll down to Angle dial Format. You can choose