Wind Reading for the Precision rifle shooter

saskcanshooter

saskcanshooter

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We all know that Wind reading is the most difficult part of long range shooting, There are ways to judge the wind speed and calculate it to enter adjustments into the scope. Post your method of judging wind speed and the way you determine the correct adjustments to make, Here is what i do.

Get my windage adjustments for a full value 10 MPH wind from 90 degrees, I use JBM ballistics to get this. I then judge the wind using indicators for example from the USMC sniper manual and US army sniper manual 0-3 MPH wind cant be felt although smoke will drift, winds from 3-5 MPH can barely be felt on the face, winds from 5-8 MPH the leaves in the trees are in constant motion.

Winds from 8-12 MPH loose paper and dust lift from the ground, 12-15 MPH wind small trees begin to sway, 17 MPH white caps form. After judging the wind i then make the correction, If the wind speed is more then 10 mph say 15 mph i divide 15 by 10 to get 1.5 and multiply that to my 10 mph full value DOPE ( data on previous engagements ) if the wind speed is under 10 mph say 5 mph then i divide 10 by 5 which gives me 2 and i divide my 10 mph full value DOPE by 2.

After i do that i determine the angle the wind is coming from, If it is coming from 12:30 ( between 12 and 1 o clock ) i multiply my previous answer by .26, if it is coming from 1:00 i multiply my anwer by .5, If it coming from 1:30 i multiply by .707, If it is coming from 2:00 i multiply by .866 and if it is coming from 2:30 i multiply by .97. Now if the wind is coming from 12:00 or 6:00 i leave my windage alone and i adjust my elevation up for headwind and down for tailwind, How much i do is dependant on Range to target and wind speed.

Thanks for Reading please post the way you do so we can all become better wind readers.
 
The 1942 US Army standard involved dropping a blade of grass and the angle your arm makes to the point where the blade lands is an indiaciton of wind speed. Divde the angle by 4 and that should be the wind in MPH.


Skip to 13:15 for the start of the discussion or 15:23 for what I was talking about

[youtube]9bmdxZwvkoQ&feature=fvwrel[/youtube]
 
Sounds like enough math to make my head explode during a 15 round match. Palm pilots, calculators, Iphones, Ipads, wind gauges etc are not allowed on the firing point. I have shot in 15 round matches where the wind has gone from 15 minutes left to 2 minutes right. I know lot of other shooter to have claimed to have shot in more extreme and faster changing conditions conditions.
This is where the wind graph you keep on your plot sheet or a plot-o-matic comes in handy.

In order to estimate the wind to put the first round on paper I use the SWAG method. I usually confirm this by having a peak at my Ma Parker wind chart. With changing wind velocity and angle changes it will give you an idea of a wind bracket.

Another method I like to use is to shoot with a cadet and let them shoot first. They usually fire their first shot with zero wind. If I estimate the wind to be 3 MOA left sure as #### their first sighter will be 3 minutes down wind.
 
The best thing I ever did was join the boys at Nokomis. Yes you take your wind readings and plot your first shot. On the line you get 2 sighters, to get you on target. When I set up my range I usually put a piece of suvey tape on each target. Watching the way the tape flies tells me the approximate wind speed.
There are a lot of factors affecting bullet path. Humidity, rain, wind, barometric pressure. The wind closest to you affects the bullet the most. Wind reading clinics helped me in that regard. From a clear morning, till rain in the afternoon the POI raised 1 moa+. Practice is the next important factor. The rifle has to be accurate enough to notice any fluctuations in wind. Load tuning/development till its a single tatered hole at 100 yards. Did I mention practice!!
 
maynard said:
Another method I like to use is to shoot with a cadet and let them shoot first. They usually fire their first shot with zero wind. If I estimate the wind to be 3 MOA left sure as s**t their first sighter will be 3 minutes down wind.
Click to expand...

That's just mean, but very effective. :D
 
tigrr said:
There are a lot of factors affecting bullet path. Humidity, rain, wind, barometric pressure. The wind closest to you affects the bullet the most. Wind reading clinics helped me in that regard.
Click to expand...

I've been doing a fair bit of reading lately. What I've read suggests the wind towards the target affects the bullet more. The reasoning was say the target is 1,000 yards out. The bullet will slow as it travels and be exposed to the wind longer in the second half of the distance.

That's not to say the wind at the shooter isn't important .. It's all important. So why do you say the wind at the shooter is more important?
 
I have started reading this book.

zipview.php


Written by Keith and Linda, they run Milcun Training Center in Eastern Ontario. Had the pleasure of attending a one day course with them a few years ago. A couple of extremely knowledgeable individuals.
 
atconner said:
I've been doing a fair bit of reading lately. What I've read suggests the wind towards the target affects the bullet more. The reasoning was say the target is 1,000 yards out. The bullet will slow as it travels and be exposed to the wind longer in the second half of the distance.

That's not to say the wind at the shooter isn't important .. It's all important. So why do you say the wind at the shooter is more important?
Click to expand...

Physics
If the wind pushes the bullet over an inch at 100 yards, then multiply that times 9. 900 yards more to go at that trajectory. Now push the bullet over an inch at 900 and you will be in the v-bull still.
 
CyaN1de said:
That's just mean, but very effective. :D
Click to expand...

You get to use all the targets and shot indicators on the range, not just your own shots on your own target:p Now if you suspect the wind has changed and you see 4-5 target frames with shots indicators all 2 minutes down wind, if you don't make a correction you will be blessed with at leased a maggy:eek:
 
maynard said:
You get to use all the targets and shot indicators on the range, not just your own shots on your own target:p Now if you suspect the wind has changed and you see 4-5 target frames with shots indicators all 2 minutes down wind, if you don't make a correction you will be blessed with at leased a maggy:eek:
Click to expand...


I just ask Maynard and divide by 2.

NormB
 
tigrr said:
Physics
If the wind pushes the bullet over an inch at 100 yards, then multiply that times 9. 900 yards more to go at that trajectory. Now push the bullet over an inch at 900 and you will be in the v-bull still.
Click to expand...

To further explain, I believe the proper way to phrase it is that the wind affects the bullet the most closest to the target (due to the bullet going the slowest at that point), but affects the horizontal trajectory, and likewise the POI, the most at the shooter, due to the wind causing the bullet to go off course at an angle early on in its trajectory.

One inch wind deflection at 100 yards equals 1MOA, and 1MOA wind deflection at 100 yards will eventually equal ~10 inches at 1000 yards. One inch deflection at 1000 yards equals 0.1MOA, and a 0.1MOA traced back to 100 yards, only equals 0.1 inches.

The wind will push the bullet more near the target, but the wind deflection at the shooter makes a bigger impact in the total deflection in POI at the target.
 
maynard said:
You get to use all the targets and shot indicators on the range, not just your own shots on your own target:p Now if you suspect the wind has changed and you see 4-5 target frames with shots indicators all 2 minutes down wind, if you don't make a correction you will be blessed with at leased a maggy:eek:
Click to expand...

Believe me, I use every wind indicator I can manage to fit into my peripheral, including target frames, mirage, grass, trees and lastly the flags.

Didn't help today though, shot a few Magpies at 300m in the fishtailing conditions....best I could manage was a 49.5/50.10
 
saskcanshooter said:
We all know that Wind reading is the most difficult part of long range shooting, There are ways to judge the wind speed and calculate it to enter adjustments into the scope. Post your method of judging wind speed and the way you determine the correct adjustments to make, Here is what i do.

Get my windage adjustments for a full value 10 MPH wind from 90 degrees, I use JBM ballistics to get this. I then judge the wind using indicators for example from the USMC sniper manual and US army sniper manual 0-3 MPH wind cant be felt although smoke will drift, winds from 3-5 MPH can barely be felt on the face, winds from 5-8 MPH the leaves in the trees are in constant motion.

Winds from 8-12 MPH loose paper and dust lift from the ground, 12-15 MPH wind small trees begin to sway, 17 MPH white caps form. After judging the wind i then make the correction, If the wind speed is more then 10 mph say 15 mph i divide 15 by 10 to get 1.5 and multiply that to my 10 mph full value DOPE ( data on previous engagements ) if the wind speed is under 10 mph say 5 mph then i divide 10 by 5 which gives me 2 and i divide my 10 mph full value DOPE by 2.

After i do that i determine the angle the wind is coming from, If it is coming from 12:30 ( between 12 and 1 o clock ) i multiply my previous answer by .26, if it is coming from 1:00 i multiply my anwer by .5, If it coming from 1:30 i multiply by .707, If it is coming from 2:00 i multiply by .866 and if it is coming from 2:30 i multiply by .97. Now if the wind is coming from 12:00 or 6:00 i leave my windage alone and i adjust my elevation up for headwind and down for tailwind, How much i do is dependant on Range to target and wind speed.

Thanks for Reading please post the way you do so we can all become better wind readers.
Click to expand...

I do similar but I do headwind and crosswind together.
CW= wind angle x sine
HW= wind angle x cosine

10mph wind
15 deg angle =CW is 15xsine=.25 .25x10= 2.6mph
15 deg angle = HW is 15xcosine=.96 .96x10=9.6mph

30 deg angle=CW is 30xsine=.5= .5x10=5mph
30 deg angle=CW is 30xcosine=.86 .86x10=8.6mph

45 deg angle=CW is 45xsine=.70 .70x10=7.0mph
45 deg angle=HW is 45xcosine=.70 .70x10=7.0mph

60 deg angle=CW is 60xsine=.86 .86x10=8.6mph
60 deg angle=HW is60xcosine=.5 .5x10=5mph

90 deg angle=CW is 90xsine=1 1x10=10mph
90 deg anglle=HW is 90xcosine=0 0x10=0mph

So in the field remember a watch face and round off our calculations for easy memory using our 10mph wind
15 minutes is a 1/4 hr
so take 1/4 of the wind(the 15deg angle)=2.5 mph
30 minutes is 1/2 hr
so take 1/2 of the wind(the 30deg angle)=5.0 mph
45 minutes is 3/4 hr
so take 3/4 of the wind(the 45deg angle)=7.5 mph
60 minutes is 1 hr
so from 60 deg and further take the full wind(the 60, 80, 90 deg)=10 mph
 
You guys do all this fancy ciphering in your head in the 1 minute you have between shots during a competition? For every shot in a 15 round string? What about fast changing conditions and fishtail winds? What about fast angle changes and increase and decrease in wind velocity.

Lets face it, we do not always shoot in constant conditions throughout the entire match. There have been way too many times every shot is like a sighter and my sights are not the same for 2 shots in the entire string. What tunnel are you guys shooting in?
 
maynard said:
You guys do all this fancy ciphering in your head in the 1 minute you have between shots during a competition? For every shot in a 15 round string? What about fast changing conditions and fishtail winds? What about fast angle changes and increase and decrease in wind velocity.

Lets face it, we do not always shoot in constant conditions throughout the entire match. There have been way too many times every shot is like a sighter and my sights are not the same for 2 shots in the entire string. What tunnel are you guys shooting in?
Click to expand...

Funny Maynard,

Im fair at reading wind and have some additional wind reading experience /mental calcs from piloting aircraft during take off/ landings.

Also I don't compete officially so I don't have to do it every few minutes between shots like you guys do.

Only the coyotes or Air Traffic Control would know if my wind reading is correct now days:D
 
maynard said:
You guys do all this fancy ciphering in your head in the 1 minute you have between shots during a competition? For every shot in a 15 round string? What about fast changing conditions and fishtail winds? What about fast angle changes and increase and decrease in wind velocity.

Lets face it, we do not always shoot in constant conditions throughout the entire match. There have been way too many times every shot is like a sighter and my sights are not the same for 2 shots in the entire string. What tunnel are you guys shooting in?
Click to expand...

I use to Formula to get a baseline with the wind for example at my last match wind was changing directions constantly and was from 12 mph to 18mph constantly i adjusted the scope for the 12mph wind coming from 45 degrees and would feel the wind on my face look at the grass the trees the flags and all the other indicators but mostly i would feel it on my face.

When there would be a lull in the wind i would fire, first round hit was in the bull at 900 yards. When the wind is all over the place i Gonculate ( to guess/calculate at the same time )

Through the entire match from 300 meters to 900 yards i never once got a shot on the white, but i didnt get every shot in the bull either. Having 95% of all the rounds youve ever fired be at long range is very helpful also.

I dont know if anyone can ever master the wind but we can defenetly improve.
 
Math on the firing line... no thanks!

I have a "wheel" for each distance with all of my dope values for wind in 3 MPH increments, for ever 1/2 hour on the clock (15 degree angle) between 9:00 and 3:00. Works the same for wind blowing from or blowing at that particular angle. I make my estimate of the wind value and angle then just look at the wheel for the dope. Quick and easy to use, quick to make with the HUD function in Ballistic FTE.
 
tigrr said:
Physics
If the wind pushes the bullet over an inch at 100 yards, then multiply that times 9. 900 yards more to go at that trajectory. Now push the bullet over an inch at 900 and you will be in the v-bull still.
Click to expand...

Wait, I don't get something. If the wind pushes a bullet an inch at 100 yards, then the wind dies. The bullet's trajectory changes, doesn't it? So, after the wind drops dead, the original path of the bullet and the new trajectory diverge, right? What you're describing seems like the original and new path of the bullet are offset but parallel.

I haven't actually shot at long ranges, so I don't know. I'm just trying to understand what's going on.
 
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