Wind and Uphill/Downhill Shots

[nimrod_gn]

Anybody know how typical ballistics software/apps handle how it calculates wind drift for long uphill/downhill shots at steep angles? Specifically when you have a shot as shown in the picture that will generate an elevation hold for 693 yards but the line of sight and also wind exposure is 800 yards. Seems to me that probably this isn't accounted for by any app or software and that we as the shooter must make the necessary adjustment for the wind hold because if we feed in a range of 693 it will just kick back windage adjustment for 693 when in reality the bullet will have a full 800 yards of wind exposure.

 

[SnakeRiverEric]

Good questions. I had a case when shooting down across a canyon, with a 20mph down draft wind. Don't think any app takes this into consideration that I know of.
The distance was 365 angle converted, yet the shot ended up about 18" low. I had to make quick adjustments to get the bull elk killed. I just figure I needed to take the wind hold and put it into the elevation calculation.

 

[elkaholic]

Good questions. I had a case when shooting down across a canyon, with a 20mph down draft wind. Don't think any app takes this into consideration that I know of.
The distance was 365 angle converted, yet the shot ended up about 18" low. I had to make quick adjustments to get the bull elk killed. I just figure I needed to take the wind hold and put it into the elevation calculation.

That's what I do, and its tricky the first shot

 

[Mikecr]

Sierra offers a good article on this, and solution in their software.
The trick is for your software to adjust PATH instead of adjusting distance.
With that, wind deflection is calculated from TOF of new path.

 

[memtb]

Anybody know how typical ballistics software/apps handle how it calculates wind drift for long uphill/downhill shots at steep angles? Specifically when you have a shot as shown in the picture that will generate an elevation hold for 693 yards but the line of sight and also wind exposure is 800 yards. Seems to me that probably this isn't accounted for by any app or software and that we as the shooter must make the necessary adjustment for the wind hold because if we feed in a range of 693 it will just kick back windage adjustment for 693 when in reality the bullet will have a full 800 yards of wind exposure.View attachment 158879

Wind would affect the bullet distance traveled "Z"....uphill/downhill, gravity affects the distance "Y" in your scenario! memtb

 

[nimrod_gn]

Wind would affect the bullet distance traveled "Z"....uphill/downhill, gravity affects the distance "Y" in your scenario! memtb

Yes, that's correct and what I said in post. Just tossing the idea out there so see how people handle this and know about it.

 

[carl1775]

Personal shooting data, from log books, on wind correction. Elevation always comes from a ballistic model, in my range finder.

 

[del2les]

Does your software have an "inclination" section?
If so and depending on software's parameters, you can enter the straight line range, wind speed, etc and the software will do it for you.

Just ran a couple of 308 test entries through mine, and they come back with about 1-2 inches in drift variance compared to 0 incline.

 

[ShtrRdy]

I think modern ballistic calculators use numerical integration to calculate the path of the bullet. This means you should be able to enter line of sight distance and angle and it will consider how the gravity is pulling on the bullet over the entire distance. Using the horizontal equivalent to estimate bullet drop is simplification and has some error associated with it.

 

[MagnumManiac]

I have pondered this exact question.
The formula used is for 'true range', regardless of angle.
Prior to purchasing a ballistic app of high quality, I actually performed written formulae for all this stuff before there was an actual app...coulda made a fortune developing an app.
Anyway, as the true range is all that matters, the apps all use this to calculate wind drift, bullet drift and Coriolis correction.
I should add that the formula that calculates true range is called Cosine, it calculates the angle you put in and determines the true range of the actual flight path, flight time and velocity at target etc.
It can be found in Speer No.13 manual, very informative piece of kit.

Cheers.

 

[Mram10us]

Makes me laugh when people explain things the OP already mentions Real answer for most of us is
"We don't know how the software computes full wind as opposed to drop compensated distance"

 

[Mram10us]

Some friends of mine called me last week asking the same question. Spike bull at 405 with shot angle at -40deg in very steep canyon. They all missed over the top and asked what the windage was doing. Great discussion of how the rfs that adjust for true distance can throw you off with winds

 

[dfanonymous]

you calculate the wind in most ballistic software for true range, not horizontal distance like your drop. So that means some software do not account for this as then OP summarized.

 

[Mram10us]

Shooter software gives:
-193.4 drop and 21" drift with 5mph at 1000yds level
-131.4 drop and 21.4" drift with 5mph at 1000yds -40deg
Correcting for angle is 766yds
-90.8 drop and 11.6" drift with 5mph