I've been working on my winds skills lately. One thing has come up and I'm trying to get a handle on what to think about it. If I'm shooting LR, 500yds let's say, and there is wind, how much wind does it take to equate a full value correction at distance. If I have a full value 10mph 9 o"clock wind for the first 50yds from the firing line, but then absolutely no wind for the remaining 450yds, does that justify a full 10mph wind correction on the target? On the flip side, what if that 10mph is still 9 o'clock, but totally consistent for the entire 500yds? Will it push the bullet the calculated full value 10mph amount or more? Thanks for any insight.
How much wind?
- Thread starter 86alaskan
- Start date
FeMan
Gold $$ Contributor
The simplest way to look at it is wind acting on a bullet causes the bullet to accelerate in the direction of the wind. If the wind stops before the bullet reaches the target the acceleration stops. Although the acceleration stops the bullet still has lateral velocity that was in part it on it by the wind and that continues at a constant rate until it reaches the target.
So in your first case the bullet will start accelerating to the right for the first part of its flight and then once it gets out of the wind it will continue to drift in a constant rate for the remainder of the travel. The net result for wind correction in that case though would be relatively small. A guesstimate would be 1 mile an hour correction say.
In your second case a constant 10 mile an hour 9 o’clock wind over the full flight path equates to a full 10 mile an hour correction.
I hope that makes sense. In my experience reading wind and making corrections is half a brain half gut.
So in your first case the bullet will start accelerating to the right for the first part of its flight and then once it gets out of the wind it will continue to drift in a constant rate for the remainder of the travel. The net result for wind correction in that case though would be relatively small. A guesstimate would be 1 mile an hour correction say.
In your second case a constant 10 mile an hour 9 o’clock wind over the full flight path equates to a full 10 mile an hour correction.
I hope that makes sense. In my experience reading wind and making corrections is half a brain half gut.
Thanks for that explanation, that makes a decent amount of sense. So, in order to achieve a full value full correction, the bullet needs to be acted upon for it's entire flight path. If it encounters any less than entirety then it would only require partial correction. Got it. seems like you'd have to shoot in a whole lot of wind for a a lots of years to get a handle on the true correction necessary.
FeMan
Gold $$ Contributor
That’s the basics. Keep in mind that everything matters but the wind at the shooter matters the most and the wind at the Target matters the least. Doesn’t matter in s constant condition but does need to be condsidered in a variable condition.
It really takes years of estimating, shooting, calibrating yourself based on feedback to get the gut tuned in. It’s a fun challenge.
I shoot Tactical and ELR where you don’t get spotters and might not see impacts. You really need to be a serious student of the wind in those disciplines. I’m always learning.
This... get a good spotting scope. Always amazes me how much wind can shift from various directions on at our 1500 range. Trees will be blowing one direction at 300 yds, lay flat at 500 yards, then grass will be going opposite direction at 900 yards.
It is not quite that simple. A bullet is much like an airplane taking off.....in that a plane or bullet will turn into the wind . When a plane has a side wind, the plane will turn into the head wind (caused by the forward speed). A bullet also turns into the wind caused by its velocity and does not proceed to the target in a linear fashion when deflected early on. You may want to look at some of Gene Beggs writings about this since he is both a great shooter and a great pilot. Good shooting...James
Alexander-M
Gold $$ Contributor
In their "The Wind Book for Rifle Shooters". Linda Miller and Keith Cunningham dedicate several pages to the discussion of how near and far winds affect the trajectory of the bullet. It is well explained, and there are many factors to consider. I bought this book for $18 from Amazon when I started in F-Class in September 2013 (*), and highly recommend it. However, it appears that it now is out-of-print, and the copies available are rather pricey. But if you can find one, it is an excellent book.
Alex
(*) PS. Thank you Immike (Mike J.) for recommending the book back then!
Alex
(*) PS. Thank you Immike (Mike J.) for recommending the book back then!
Dusty Stevens
Shiner
the closer the wind change is to the muzzle the more important it is.
There are too many variables that all have to be guessed too accurately.
The math is too complicated. Especially for anybody to do in their head at the line.
Determining wind effect accurately and scientifically is clearly impossible.
The only rational conclusion is the winners of long range shoots are witches!
The math is too complicated. Especially for anybody to do in their head at the line.
Determining wind effect accurately and scientifically is clearly impossible.
The only rational conclusion is the winners of long range shoots are witches!
I assume all your comments here are tongue in cheek.
I assume all your comments here are tongue in cheek.
Not entirely.
I'm not that experienced but it does look to me that for complicated conditions the physics problem is too difficult for anyone to stand on the line and solve accurately enough to put the first bullet in the x-ring.
I don't even know if that statement is a radical claim or "duh".
Pick up everything you can find on wind and reading wind. I recommend the USMC Marksmanship Guide for service rifles, MSG Jim Owen’s books, and begin there. Consider the direction you are firing as 12 o’clock. Any wind at all from 9 or 3 o’clock is a full value wind. Wind closer to the shooter will affect the projectile the most because it happens as the round leaves the barrel. Think of the angular measurements of a MOA, And you can see that a small change here will become greater at distance.
Then, go out and shoot in the wind. Concentrate on the conditions, direction and velocity. Make very good notes. Learn to watch and observe the conditions. I have been doing it over 40 years. I am just getting good at it. It is truly a lifetime study.
The hardest part of reading the wind for long range competition is sifting through all the misinformation you receive on the internet.
I admit that I am no expert on the subject. But I can promise you when you are competing at 1000 yards if you are paying more attention to what's happening 30 yards out than you are to what's going on about 800 yards out you most likely will get beat.
I know that goes against most the math and the experts, but it is true.
I admit that I am no expert on the subject. But I can promise you when you are competing at 1000 yards if you are paying more attention to what's happening 30 yards out than you are to what's going on about 800 yards out you most likely will get beat.
I know that goes against most the math and the experts, but it is true.
If you get the chance, go to the range when it is raining or a light snow. If you can see the target you can hit it. More importantly, you can see what the wind is doing all the way to the target. You can also see how the wind velocity and direction changes. This is a great condition to learn about wind and how it affects your bullet.
In the Bulletin here on this site, about halfway down the page, is a 5 part video series from the USAMU.
Part 5 explains how to judge wind direction, speed and the effects they have on a bullet.
Part 5 explains how to judge wind direction, speed and the effects they have on a bullet.
Real question or rhetorical?
Wind in the first 1/2 will have double* the effect of the second half.
But you made the second half wind 3 1/2 times greater, so it will dominate the net effect.
I get roughly .2" from the light,early wind and .3" back the other way from the late, heavy wind.
* somewhat more than double but the precise math is hard and the linear ballpark approximation is easy
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