4 dof angle and wind issue?

stan_wa

Lil-Rokslider
Joined
Aug 6, 2020
Messages
218
Location
Washington
When I use a high angle shot and wind combination, headwind or tailwind. I’m getting a result that doesn’t seem right to me. I noticed this after trying to take a 30° downhill shot at 700 yards on a rock.

If you take a look at the 4 screenshots below, you will see that the effect on come up aka bullet drop is significantly different between head wind and a tailwind when there’s angle applied.

I know at moderate angles, horizontal compensated distance can be a good alternative, but in the user guide for the 4 dof program, it advises against using horizontal distance in favor of baking it into the solver.

My theory is that it’s considering a headwind or tailwind to have a component working in line with gravity, when shooting at an angle. kind of like wind, drift but , upwards, or downwards, but the effect on drops seems much too large.

Notice that headwind versus tailwind at 800 yards makes .1 MOA difference in drop for a level shot but about 4 moa difference when applied to a 26 degree angle shot.

Should wind and angle solutions be trusted?
Is the result realistic? my field testing says no
 

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khuber84

WKR
Joined
Jun 6, 2019
Messages
1,069
Here's my 6gt prs rig, 4dof kestrel and AB kestrel. First slide is 10 mph tail wind 0° incl, then -26° with tail then same angle with head wind. I haven't shot at such extreme angles to know what solution holds true, but I'd be thinking 4dof is grossly over calculating the affects of the tail wind on lift. 4dof headwind call is only 3" different of impact VS AB call. At 860y most of us don't have rifles or shooter ability to see that difference.
Keep in mind, uphill shots are positive angle, downhill are negative.
20230603_152317.jpg20230603_152459.jpg20230603_152525.jpg
 
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stan_wa

stan_wa

Lil-Rokslider
Joined
Aug 6, 2020
Messages
218
Location
Washington
I agree the 4 dof tail wind seems crazy different that can’t be right
 
Joined
Oct 4, 2015
Messages
334
I just tried it in geoballistics for my 300 Norma and it's a .7 mil different at 850 yards. Seems like it fall right between 4dof and ab?
 
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