Reading Wind

[Old Tanker]

I watched the video of Emil Praslik discussing how to read wind. Very informative. Using a ballistic calculator and a data from a favorite .308 load, I started checking MOA corrections for 1 MPH wind 100 out to 600. Since the natural drift of the bullet, in no wind, is left to right, do you have to account for that drift in a left to right wind? More correction for left to right wind than for right to left in a wind of the same speed?

 

[Fast14riot]

Aerodynamic jump should be part of your no-wind zero for each distance.

 

[Terry]

Redirect Notice

 

[RegionRat]

OldTanker, all of this depends on how you are doing the ballistic solution, as in are you using a comprehensive ballistics solver or are you pulling individual calculations?

These are vector quantities and they have to be summed up to get a final value, just as you suspect.

Using something that does a comprehensive ballistic solution takes all that work out of it for you. What they call "lite" versions means that some factors are neglected at shorter distances, "full" versions are used for longer calculations and more serious work. Full versions include spin drift, Coriolis, aerodynamic jump, etc., for example.

To see if your solution is including spin drift, use a 100 yard zero and change the direction of the wind. Look at the values out a longer distances and you should see that bias.

 

[Old Tanker]

Aerodynamic jump should be part of your no-wind zero for each distance.

Thanks. So just add or subtract that factor at each distance?

 

[Old Tanker]

OldTanker, all of this depends on how you are doing the ballistic solution, as in are you using a comprehensive ballistics solver or are you pulling individual calculations?

These are vector quantities and they have to be summed up to get a final value, just as you suspect.

Using something that does a comprehensive ballistic solution takes all that work out of it for you. What they call "lite" versions means that some factors are neglected at shorter distances, "full" versions are used for longer calculations and more serious work. Full versions include spin drift, Coriolis, aerodynamic jump, etc., for example.

To see if your solution is including spin drift, use a 100 yard zero and change the direction of the wind. Look at the values out a longer distances and you should see that bias.

Thank you, that’s what I thought. I’m using Hornady’s ballistic calculator (because it downloads for free). My .308 Tika is a hunting rifle so I may shoot it to 600 on the range but I’ve never taken game beyond 250. I think my, off the shelf, 6.5 CM is capable of Xs at 1000. Beyond that, it goes subsonic fairly quickly. I just want to improve wind calls and shooting skills.

 

[Depart123]

I watched the video of Emil Praslik discussing how to read wind. Very informative. Using a ballistic calculator and a data from a favorite .308 load, I started checking MOA corrections for 1 MPH wind 100 out to 600. Since the natural drift of the bullet, in no wind, is left to right, do you have to account for that drift in a left to right wind? More correction for left to right wind than for right to left in a wind of the same speed?

I turn all that stuff off.

Spin drift amounts to about 1% of drop. If you are using 25moa of elevation to hit the target, then dial in 0.25moa (left) for spindrift. All the calculators over compensate in my experience.

 

[JFrank]

Scrolling down you'll find additional threads on the subject, we also have a thread - Windtalkers

 

[Fast14riot]

Thanks. So just add or subtract that factor at each distance?

Yes, basically your no-wind zero moves as you get farther out. My 260AI with a 200y zero, I add R0.5 moa to my zero automatically for 1000 yards.