Cool, thanks i will. I like those bullets for coyotes... they drop them stone dead, but maybe on a windy day i need to look for an alternative.
So how do you guys figure out your drift in the field? You get there, pick your spot, have a good idea of wind speeds know your distance... but you dont have a calculator or your computer with you... is it going to be 2" or 4"...
Does this just come from experience and is basically an estimation, or do you carry those fancy wind speed machines...?
The formula I gave you earlier is simple enough to use on the fly, and generic enough to be viable across a wide velocity spectrum, but as Stubblejumper said, to get good at shooting in the wind, you have to shoot in the wind.
I borrowed a Kestral wind meter with the built in A-Trag ballistic program from a local fellow and used it for a couple of months. Its good enough to be a worthwhile expenditure for a dedicated long range shooter, but I doubt that a varmint or big game hunter would get the value from it. What it does is measure real world wind, humidity, and temperature, and produce a firing solution for the range at which you intend to shoot, based on your specific bullet and velocity. And its correctable for variances in velocity and BC. The downside of this little wonder besides it's cost, is that the small screen can be difficult to read in bright sunlight, like you might have on a clear cold day in the winter, when sunlight is reflected back off the snow. What is kind of neat is that the firing solution is seldom static, as wind drops and rises, and atmospheric pressure changes, the solution is constantly in flux which reflects true conditions.
What I use primarily now for long range shooting is a load specific whiz-wheel from Accuracy 1st. You send them your instrument velocity and bullet specs, and they will produce the whiz wheel specific to that bullet and velocity. The solution is also velocity/BC correctable, and you enter most of the same parameters that you would with the A-Trag, except you don't have a weather meter fine tuning the solution.
That's all fine for shooting at long range, but for practical shooting at live targets, over the ranges that are typical when hunting, a simple wind formula that you can use on the fly is more appropriate and will still put you on target . . . if you practice.
Estimating wind speed is simplest with a flag, provided the wind speed is under about 25 mph. You look at the angle of the flag or wind sock to the pole, divide the angle by 4 and that gives you the wind speed in mph. If the flag sticks straight out at 90 degrees, the wind speed is about 22 mph, if it raises slightly, it is about 25 mph, but here is gets tricky because a stronger wind will not raise it any higher than a 25 mph wind. If the flag only rises to about 22 degrees, the wind speed is 5 mph, 45 degrees its 10-12 mph and so on. Experienced long rang shooters can do a similar thing with mirage.
By now your yelling at the computer, "So who carries a flag into the field with them!!??" A field expedient solution to this problem is to carry a rag, about 12" square. Hold it between your thumb and finger with your arm extended out at shoulder height, let the rag drop, then point to it at the moment it first hits the ground. The angle between your body and your arm when you point to the spot the rag contacted the ground is divided by 4, which gives you your wind speed in MPH.
Soak them in a bucket of steam for a few hours this will cut down on drift.
