Reading the wind.

[farmerj]

I won't take credit for something that's taught in a lot of rifle courses. But here's a nice little link to learn about reading wind.

Outside of the bullet drop, this is the hardest to adjust for. It can change in the blink of an eye.

Position is important too, but wind will rule any day. hunting or on the range.

http://www.longrangehunting.com/article ... g-wind.php

Notes on wind velocity:

* 1-3 mph will move dry tall grass
* 2-4 mph - you can just feel on your face, large leaf, light stems move like maple leaves
* 5-6 mph - mirage tips 45 degrees
* 5-6 mph – flat lines a 24” piece of flagging ribbon
* 4-8 mph – will make small leaf, heavy stalks move like alder
* 6-10 mph – will move the tips of short needle trees like larch & spruce
* 10 mph – mirage starts to flat line
* 8-12 mph – will make brush like alder, small aspen etc start to move
* 10+ mph will make trees start to move



Giving a value to the wind is easy once a direction is determined. A 90 degree wind from either direction is a full value wind. These next angles get the following values:

* 90 degrees - full value
* 60 degrees - .85 value
* 45 degrees - .70 value
* 30 degrees - .50 value

[mnmike59]

Great info. Thanks. Ive recently acquried an interest in long range rifle, I can't wait to see what this will cost me.

[PhilaBOR]

Anybody shoot the Elk River F-class weekly events? I made it to two of them last year and hope to make a few this year. Lots of fun.

Phil

[Grandpa Rex]

I recall years ago a chart for determining wind speed from observing a standard American flag...I tried to find it again recently with no luck.

Anyone know a source?

[farmerj]

I recall years ago a chart for determining wind speed from observing a standard American flag...I tried to find it again recently with no luck.

Anyone know a source?

http://www.snipersparadise.com/marksmanship/weather.htm

Angle of the Dangle.... Divide the angle by 4.

The flag method is the most common method used to estimate wind speed. A flag blowing in the wind will naturally blow away from the flagpole, with the angle of the bottom of the flag to the flagpole increasing with increasing windspeed. To estimate the wind speed in mph, the angle in degrees between the bottom of the flag to the flagpole at the mid-range position between the shooter and the target is divided by 4. For example, an angle of 60 degrees between the bottom of a flag and a flagpole would be estimated as a 15 miles per hour (24 km/h) windspeed.


The most desired method of determining wind is by reading mirage. A mirage is a reflection of the heat through several layers of air at different temperatures and density. A Sniper can see the mirage as long as there is a difference in ground and air temperature. In order to see this mirage the Sniper must focus his spotting scope on an object at midrange, then place the scope back onto the target without readjusting the focus. As observed through the telescope, the mirage appears to move with the same velocity and direction as the wind, except when blowing straight into or away from the scope. Then the mirage gives the appearance of moving straight upward with no lateral movement. This is called a " boiling mirage." In general, changes in wind, up to 12 mph can be readily and accurately determined by observing the mirage.

[goalie]

The most desired method of determining wind is by reading mirage. A mirage is a reflection of the heat through several layers of air at different temperatures and density. A Sniper can see the mirage as long as there is a difference in ground and air temperature. In order to see this mirage the Sniper must focus his spotting scope on an object at midrange, then place the scope back onto the target without readjusting the focus. As observed through the telescope, the mirage appears to move with the same velocity and direction as the wind, except when blowing straight into or away from the scope. Then the mirage gives the appearance of moving straight upward with no lateral movement. This is called a " boiling mirage." In general, changes in wind, up to 12 mph can be readily and accurately determined by observing the mirage.

This is why a GOOD spotting scope (or riflescope) means good resolution, not necessarily high-power. Too much power will often leave you unable to see the mirage, especially with poor resolution.

Mmmmmm, drooling over one of those tripod-mounted team scopes fro Unertl......

[Rip Van Winkle]

If anyone's interested, I found these on my hard drive from years ago when I use to shoot 30 cal.

The numbers at 6 & 12 o:clock are wind speed, the other numbers in the circle are windage corrections in 1/2 minute clicks and the Roman numerals on the outside are wind direction.

[farmerj]

Those will work for more than just the .30 cal too.

the M855 and M80 ball ammo have very similar ballistics and as such, the come-ups and wind holds are very close and similar.

One of the nice things of using surplus ball for practicing. 5.56 is cheap compared to 7.62.

[Pat]

More stuff to make me realize how little I really know. Holy smokes!

[goalie]

A friend of mine wrote a nice article on reading the wind, I think it was for Precision Shooting magazine. I'll look it up and post it.

[goalie]

Here's that article. Emil is from NY, but we got into some trouble together back in the day right here in St Paul chasing women when we were not playing chess or training cops up at Ripley.

http://www.6mmbr.com/windreading.html