Long Range Shooting Thread

[Meketrefe]

The conclusion on that paper is wrong and if you divide the example I put in 3 zones you will find out that the 2nd and 3rd zones have a greatest effect
on the wind than the first one. I divided in two zones for simplicity and knowing this is a subject for confusion sometimes.

In the example I posted above with 2 zones you can clearly see the bullet takes more time to travel the same distance due to the lower speeds / deceleration.
This are the physics on paper. Physics are supported by the math and the math I am showing demonstrates what I have been saying.
55" - 34.2" = 20.8" DIFFERENCE. The initial chart was done with my own ballistics calculations that I created in excel but if you put these zones in any ballistics calculator you will see the same or almost similar cards depending on BC adjustments and what not but the overall result is the same. An object travelling slower takes more time to cover the same distance than traveling faster. I know you know this.

Here give it a try if you want... hornady's one will do... http://www.hornady.com/ballistics-re...ics-calculator

Let me give you another example. Lets say you read a 20mph 3 o'clock wind during the first 500 yards. Then in the last 500 yards you read a 20mph wind
going 9 o'clock. How would you adjust? Would you say they cancel each other out or something else?

I wished more people participated on this thread so we could get other points of views, explanations or questions.

We will get there! lol.

[Meketrefe]

Trajectory with drag...

https://en.wikipedia.org/wiki/Trajec...f_a_projectile

[WARFAB]

The angular deflection per yard is consistent, but the angular deflection from the first half of the bullet flight gets magnified more by the remaining distance to the target.

With no wind in the second 500 yards the deflection is still greater than half of what it would be with wind in the second 500 yards.

The bullet doesn't return to a flight path parallel to the bore axis when the wind stops at 500 yards. It continues traveling on a straight path roughly tangent to it's wind induced flight curve.

Edit: The red text in the graphic should read "No Wind 500-1000"

[thughes]

I have nothing to contribute but I do find this discussion fascinating, please continue.

[big flash]

I’m not a subject matter expert at all but the way I understood which wind was more important before the charts and graphs here was basically as follows.

All else being equal, the wind at the shooter position has the ability to change the angle sooner in the flight path, therefore the miss has the ability to be larger the further you go down range. However the bullet is traveling faster and therefore is affected by outside forces less than at range.

All else being equal, the wind closer to the target has the ability to change the bullet more because the bullet is going slower and therefore is more subject to outside forces. However the distance of the flight path left is less.

but nothing is equal, so it's going to depend on the distance, the load, the speed, the drag coefficient, the strength of the wind, the distance at which the bullet is exposed to the wind, etc. etc.

[Meketrefe]

Hey, we got two more people interested in shooting related material! That is so cool! LOL

Warfab,
Thanks for the curved charts. You are right the paths are curved and not straight as I reflected. I just over simplified with arrows for illustration purposes. Angle effect is cumulative on the trajectory so we are on agreement there. The thing is the trajectories are not perfect parabolas as they are affected by drag exponentially. The effect the extra time the bullet takes
to reach the target in the 2nd half (sometimes double the time to cover the same distance) has a greater effect than the effect on the virtual "starting" angle due to miscalculation in the first wind zone. Drag formulas whether they are based on gravity, wind or anything else they are all exponential. The further away from the axis the more aggressive they get exponentially. This is
consistent with the time increase due to deceleration.




I think in ballistics it is better to use examples and then develop the explanations from there. In the example above of 10mph one direction in the first half and the 10mph on the 2nd half going
the oposite direction how would you manage that? Would you leave it with no correction? Or if you make an error call in either zone do you think the 1st will have far more effect?
This 10mph with two zones is a very popular example used in marksmanship training to understand wind zones and verify your own simplified formulas.

I did some searches and found this guy. He doesn't get into it in detail but it is a good quick video to watch specially for anyone starting on wind reading...

[WARFAB]

The differences in wind zone effects become even more apparent when you split the range into 3 sections.

Ballistics-2.gif

[Liberty's Teeth]

Meke and Warfab, you two are having a great conversation here. Please keep it going for our learning!
Do either of you know if meplat tuning would modify the behavior of the bullet in flight from within your data sets?

[WARFAB]

Do either of you know if meplat tuning would modify the behavior of the bullet in flight from within your data sets?

Meplat tuning would lower the BC slightly. My understanding is that meplat tuning is done to ensure consistency only. The manufacturing process leaves slight inconsistencies in the tip of each HP bullet. The theory is having the exact same BC every bullet is more advantageous than having a slightly higher BC that changes from shot to shot.

If I can't accurately call the wind I figure meplat uniforming is kind of pointless.

[Liberty's Teeth]

Sitting here reading the discussion points and the data is rather fascinating. The one thing I am curious about is relating to the orientation of the bullet during flight. You have been discussing a full value wind in the examples but from the 1000 yard line the bullet sees full value at the muzzle then it transitions through half and almost quarter value by the time it reaches the target. Is this correct or are you saying that yaw keeps the full wind value on the bullet?

[WARFAB]

That's a complex question.

My only thought is that the bullet axis doesn't remain parallel to it's flight path horizontally or vertically. How all of that impacts the final destination I have no idea. I'll try not to think about it and assume it's all covered in the ballistics calculator.

[Meketrefe]

Metplat is mainly to make the actual Ballistic coeficient consistent from one bullet to the next. It can also improve the actual BC so it is good to test it after metplat work and adjust the BC
that can be done with two reference impact points and a ruler calculating the delta (difference).

Warfab,
All wind is important. The more zones we introduce the less significant is the discussion because the errors on the shooters side will always have an effect in the entire trajectory that is true and they are compounding that is also true. We already agreed on that.
So that is why it is better to partition this in two zones but most importantly two zones in the middle that is the whole purpose of the wind reading with mirage or by other means.
With 3 or even 4 zones all we do it is to pull away from the practical use of reference points.
This whole discussion started because the people worry too much about the wind a the shooting position yet the errors downrange are the ones that trow people off target
and this also because the readings at the shooter location are normally more accurate (kestrel) versus having to estimate the wind at a further location but also because
the effect of that wind downrange has greater effect than originally though because the bullet decelerating progressively.

[WARFAB]

This whole discussion started because the people worry too much about the wind a the shooting position yet the errors downrange are the ones that trow people off target and this also because the readings at the shooter location are normally more accurate (kestrel) versus having to estimate the wind at a further location but also because
the effect of that wind downrange has greater effect than originally though because the bullet decelerating progressively.

That would be the point we disagree on.

Who'd have thunk we'd actually have a good shooting debate on a shooting forum? Good times.

[Meketrefe]

And BTW I am glad more people are joining the thread. It is good to see folks enjoying the discussions. In the end it is all good and to suck a bit less every day, including me.

[WARFAB]

Side note: The article I linked to and quoted earlier is by Dan Periard. I just discovered that he's an Applied Ballistics employee despite that article being published under a different company.