Hornady ballistic App incorrect wind?

[CA_Shooter]

I'm trying to make sense of the Hornady app vs a wind diagram. I am seeing inconsistencies

Looking at the following, I will show the comparisons. Using the Hornady app for 2700 FPS and 30 mph wind in various directions: 3, 7, and 12 o'clock:

According to the wind vector chart attached, by vertical wind direction should be:

3 highest
7 middle
12 lowest

Hornady app is showing different, in MOA correction from a 100 yard zero:

3 = 12.67 MOA correction
7 = 14.12 MOA correction
12 = 13.78 MOA correction

From the vector chart, if I'm reading it correctly, then:

•3 should have the most MOA correction
•7 should have the second most MOA correction
•12 should have the least MOA correction

Am I looking at this wind vector chart correctly? And if so, seems the Hornady ballistics app doesn't work

 

[Coyotefurharvester]

12 o'clock wind lowest bullet strike , wind at your 6 highest impact. Right hand twist.

 

[nmjwolf]

I'm trying to make sense of the Hornady app vs a wind diagram. I am seeing inconsistencies

Looking at the following, I will show the comparisons. Using the Hornady app for 2700 FPS and 30 mph wind in various directions: 3, 7, and 12 o'clock:

According to the wind vector chart attached, by vertical wind direction should be:

3 highest
7 middle
12 lowest

Hornady app is showing different, in MOA correction from a 100 yard zero:

3 = 12.67 MOA correction
7 = 14.12 MOA correction
12 = 13.78 MOA correction

From the vector chart, if I'm reading it correctly, then:

•3 should have the most MOA correction
•7 should have the second most MOA correction
•12 should have the least MOA correction

Am I looking at this wind vector chart correctly? And if so, seems the Hornady ballistics app doesn't work

Are you referring to elevation or windage correction -- the Hornady 4 DOF app is very accurate in my experience. It seems like the numbers you are referring to would be for elevation corrections from the app and not windage.

 

[CA_Shooter]

12 o'clock wind lowest bullet strike , wind at your 6 highest impact. Right hand twist.

Yes. Hornady app has 7 as a higher elevation correction than 12.

Are you referring to elevation or windage correction -- the Hornady 4 DOF app is very accurate in my experience. It seems like the numbers you are referring to would be for elevation corrections from the app and not windage.

I am only referring to elevation corrections

 

[FeMan]

I think you are reading it correctly. 3 o'clock has a 1.11 moa difference compared to 12 o'clock and 7 has a 0.34 correction. Leave the wind heading at 12 o'clock and cut the wind value to see if the program is making any adjustment for it. I doubt it is but could be wrong.

FWIW, I shoot a lot of LR in different field conditions. I have seen head and tail winds blow bullets all over the place and produce lots of vertical stringing you wouldn't otherwise see. I have not seen reliable and repeatable lowering of impacts in a head wind and raising in a tailwind however.

I apply the Magnus jump and spin drift along with the lateral wind vector based on cosine and wind speed. I shoot 12 o'clock as straight up if it truly is with no vertical correction. If the wind is 30 mph figuring out the actual lateral component will make a much larger difference. Wind is almost never exactly 12 o'clock.

I know they say the headwind/tailwind vertical is there and predictable, but I haven't found it myself.

 

[CA_Shooter]

I think you are reading it correctly. 3 o'clock has a 1.11 moa difference compared to 12 o'clock and 7 has a 0.34 correction. Leave the wind heading at 12 o'clock and cut the wind value to see if the program is making any adjustment for it. I doubt it is but could be wrong.

FWIW, I shoot a lot of LR in different field conditions. I have seen head and tail winds blow bullets all over the place and produce lots of vertical stringing you wouldn't otherwise see. I have not seen reliable and repeatable lowering of impacts in a head wind and raising in a tailwind however.

I apply the Magnus jump and spin drift along with the lateral wind vector based on cosine and wind speed. I shoot 12 o'clock as straight up if it truly is with no vertical correction. If the wind is 30 mph figuring out the actual lateral component will make a much larger difference. Wind is almost never exactly 12 o'clock.

I know they say the headwind/tailwind vertical is there and predictable, but I haven't found it myself.

At 12 o'clock, going from 0 to 40 mph wind only makes a .40 MOA (2 inches) difference at 600 yards using the app.

At 3 o'clock 0 to 40 mph wind is a difference of 1.3 MOA (9 inches) at 600 yards.

Does that seem right?

 

[FeMan]

It does not seem correct to me. I put the same thing in my Kestrel and got 0.2 moa lower impact with a 40 mph headwind and a 0.20 moa higher impact with a 40 mph tailwind at 600 yards. The 0.2 moa and the same value makes sense to me. I believe the 1-inch of vertical comes from a higher or lower velocity relative to the surrounding air and the increased or decreased drag. Having a different value from a tailwind vs a headwind defies the laws of physics as far a I know.

I have shot in winds like that and just getting an impact somewhere in the right zip code can be a struggle. I cant imagine there is any practical way to test this and sort it out of all the other factors in winds like that.

Hope that helps.