Advanced Marksmanship What wind values to put in a written Chart

[Jack Master]

What are the best 2 or 3 wind speeds to put into the printed data chart?

This winter I got a new rifle and have doped it out to distance. I am also making paper charts for it. I started to ask what are the best 2 or 3 wind speed to put into the printed data chart? So I sat down to figure this out.

Recently I have observed a lot of shooters putting down their Gun Mile Per Hour speed. Why would you do that? The purpose of the Gun MPH if be able to easily memorize these numbers. This means there is not reason to write them in the chart. I am guilty of this, I used to do it too.

Most shooters want to put 5-10-15mph on their charts, but I don’t think this is the best answer. Especially if we are shooting small targets at further distances. If we have one of these values (5,10, or 15mph) in our chart we can get the other values. For example, if 5mph is in the chart we can double it’s hold to get 10mph and triple the hold to get 15mph. Wind, as a function of speed, is a linear value. 5-10-15-20 or 2-4-6-8-10 can all be calculated by adding multiples of a written speed.

I listed out the possible options in the table below. I decided to focus on wind speed 30mph and less and wanted to limit the chart speed to 10mph maximum.

In the chart above you can see the values of 1mph and 2mph (by dividing 2 in half) can be used to find a wind hold for every wind speed. But, using such a small value allows for compounding errors when multiplying by a large wind speed. If we used 1mph chart value and have an 18mph wind speed, we could multiply a small error 18 times and get a wrong wind hold.

Example of Error induced by using a small speed value
1mph hold = 0.22mil - Actual 18mph hold = 18x0.22=3.96mil,
1mph Chart Value = 0.2mil - Chart 18mph hold = 0.2x18=3.6mil
Our error is 0.4mil due to rounding errors. This is an easy target miss at any range.

To avoid this rounding issue we can use larger values like 10mph and use a percentage of it.
10mph hold = 2.23mil - Actual 18 mph Hold = 2.23 x 1.8 = 4.01mil
10mph Chart value = 2.2 - Chart 18mph Hold – 2.2 x 1.8 = 3.9 mil (1.8 comes from 18mph/10mph)
Error is 0.1mil

But rather than deal with multiplying by 1.8: Can I use a different value to get there? If I had 6mph in the chart I could use 6mph hold time 3 (6mph x 3 = 18mph)
6mph hold = 1.34mil - Actual 18mph Hold = 1.34 x 3 = 4.02mil
Chart value = 1.3 Mil - Chart 18mph Hold = 1.3 x 3 = 3.9mil.
Error= 0.1 mil

Having 6mph available in the chart is an advantage to do faster, easier mental math.

So the question is what 2 or 3 wind speeds should I use to get the best chance at using a simple multiple of a number to get to the most available wind speeds. 6-8-10mph have proven to the be the most effective as pointed out in the chart below. There are 12 single value wind speeds that cannot be easily calculated if you have 6-8-10mph in our chart (40%). Seven of these numbers are Prime numbers. This means only 1 and half of 2 (1) can be used to find them and as pointed out above that’s not a good idea due to the rounding errors. This leaves 5 values that I cannot easily do a multiple of. That pretty darn good.

If we allow the wind speed holds in the chart to be divided further in to 1/3s or 1/4s we can reduce this to 1 value that I cannot easily multiply (plus the 7 Prime Values) and that is a 1mph wind speed. This means we are covering every possible speed between 1 and 30 except 1 (plus the 7 prime values). This is nearly a perfect condition.

I will be using 6-8-10 mph in my wind chart from here forward. It makes mathematical sense.

 

[Makinchips208]

I would have to reread that to comprehend it, but I think I get where you are going. But I still don’t see the point in doing that if you use the MPH method.
So if I were to write any wind holds I would put wind holds for the mph of my gun. My 308 is 4 mph gun so I would only write holds for that wind speed. Point being I am just reinforcing the proven method of gun mph.

 

[BLKWLFK9]

Jesus. That hurts my head. You're going to have to dumb this down for me when u get here. Maybe on the ride from the airport.

 

[Near miss]

To avoid this rounding issue we can use larger values like 10mph and use a percentage of it.
10mph hold = 2.23mil - Actual 18 mph Hold = 2.23 x 1.8 = 4.01mil
10mph Chart value = 2.2 - Chart 18mph Hold – 2.2 x 1.8 = 3.9 mil (1.8 comes from 18mph/10mph)
Error is 0.1mil

This will be needed to be explained in more depth. Otherwise a very nice solution! It covers very well all other numbers except the 1 and 2 which are easily estimated using mph.

I also do think the the wind values themselves should maybe used in 10% of 10mph, not calculating the 1mph 10 times for the 10mph wind. Probably depending on solver and roundings used, you could end up with a lot of error. Noticed this when making list myself.

 

[SonoranPrecision]

I understand what you are doing, and on paper, it makes perfect sense. That said, in practice, I think it may be more complex and precise than is necessary, given how quickly wind conditions can and do change. I find using the gun mph method to be more than enough to get the job done. Additionally, I have found any error that is built in to be lost in the noise of the wind’s variability.

 

[Near miss]

I understand what you are doing, and on paper, it makes perfect sense. That said, in practice, I think it may be more complex and precise than is necessary, given how quickly wind conditions can and do change. I find using the gun mph method to be more than enough to get the job done. Additionally, I have found any error that is built in to be lost in the noise of the wind’s variability.

This is true, it is not going to make obvious improvements but wind call is always about precision and hitting is timing that taking the shot when the condition matches.

I mainly bracket the wind to min and max and try to work between those. After that I use mils for wind calls, say .5 and 2 mils, and since I "know" it is lowest at .5 I try to match my hold to wind condition.

But wind rhytm and intensity cannot be the same everywhere, I bet there are hunreds of identifiable wind conditions and at least ten easily recognizable. So every shooter must pick the best way to convert their wind call to a number or numbers (bracket) at that certain range and conditions. I try to choose the most prevalent wind or the one I can easily identify at the range from movement.

 

[SonoranPrecision]

This is true, it is not going to make obvious improvements but wind call is always about precision and hitting is timing that taking the shot when the condition matches.

I mainly bracket the wind to min and max and try to work between those. After that I use mils for wind calls, say .5 and 2 mils, and since I "know" it is lowest at .5 I try to match my hold to wind condition.

But wind rhytm and intensity cannot be the same everywhere, I bet there are hunreds of identifiable wind conditions and at least ten easily recognizable. So every shooter must pick the best way to convert their wind call to a number or numbers (bracket) at that certain range and conditions. I try to choose the most prevalent wind or the one I can easily identify at the range from movement.

Right, and I do the same. All I was saying, was by the time the OP reverse engineers his super precise wind call, the conditions have changed. Even if he is just using it to make a range card with wind brackets, he now has to do it at every distance he’ll be shooting. And by the time he’s done writing his card, the conditions may have shifted to the point of making the card irrelevant. Using a gun number is fast and easy to do on the fly when switching targets/distances.

 

[brianf]

im following both opinions

something i need clarification on is what discipline are we discussing

while every tool works, the conditions and task may dictate which one is more efficient

...not better just more efficient

if i have all the time in the world why wouldn't i just use my kestrel or calculator with a dope chart for that specific rifle/load combo and get the perfect calculation?

if im in a more dangerous environment, would i even have time to think of MPH?

i would think if i was in that environment i would know my ballistics like the back of my hand

if i shooting BR or F-class im choosing which flags give me the most consistent info i can decipher, the getting the perfect solution plus sighters etc

i really like the MPH idea and it works very well, but making a chart that i still have to do "hard math" takes the same amount of time at home as making a chart with simplified information

if im wrong just bash me lol

 

[_Windrider_]

Why not just use 1 and 10 mph? i can calculate easily any number as a percentage if i know these. But like you said thats in a dynamic environment. Time and opportunity allow me to use other tools. I try to use the kestrel to just update my brain as conditions change so i have a basic understanding of the steady state conditions and i can adjust from there. if steady state was 17mph and it goes down 4 mph i just adjust by 1 mph hold times 4 at the given range.

Now i am not discounting at all Teds method here. for field cards i think its a solid methodology. for analytical purposes i think its as solid as it gets, but i guess im always looking for something fast in my head that doesnt require a whole lot of memorizing to many different numbers. and anytime you can work in base 10 its so much easier, hence mils are better than MOA.

im following both opinions

something i need clarification on is what discipline are we discussing

while every tool works, the conditions and task may dictate which one is more efficient

...not better just more efficient

if i have all the time in the world why wouldn't i just use my kestrel or calculator with a dope chart for that specific rifle/load combo and get the perfect calculation?

if im in a more dangerous environment, would i even have time to think of MPH?

i would think if i was in that environment i would know my ballistics like the back of my hand

if i shooting BR or F-class im choosing which flags give me the most consistent info i can decipher, the getting the perfect solution plus sighters etc

i really like the MPH idea and it works very well, but making a chart that i still have to do "hard math" takes the same amount of time at home as making a chart with simplified information

if im wrong just bash me lol

 

[Jack Master]

something i need clarification on is what discipline are we discussing

This is the best question. Thank you
This discipline/purpose of this is pointed at newer shooters. Maybe someone who does not grasp the gun MPH method yet. Think "day 2" of shooting. Once the Gun MPH is figured out its what I recommend because its so fast. But for new shooters in a low stress environment, with one target, that have time to study and figure out the wind using 6-8-10 gives them the most options for the best result. Maybe its a shooter that is learning to read the wind and work on thier wind process. Some shooters never grasp the Gun MPH method. (yearly hunter that shoots 20 rounds a year and stays within 400yds)

My 308 is 4 mph gun so I would only write holds for that wind speed

Honest questions: Why would you write this down?
Its meant to be memorized and fast action. I used to do this too but then asked myself why and decided to stop writing down what I already know.

given how quickly wind conditions can and do change. I find using the gun mph method to be more than enough to get the job done

Agreed on both of these points. An advanced shooter can manage the wind changes and the gun MPH. Not all long range shooters will be able to do this, that's who this is pointed at.

Why not just use 1 and 10 mph?

If you used these together it might work, I had not analyzed this option. But to get 18mph wind i'd have to do (10mph hold x 2) - (1mph hold x 2) This could be a good option to reduce the rounding error and be somewhat speedy. I still think (6mph hold x 3) is faster and less brain work., but maybe its a personal preference.

-----------------------------------
Here is an example of the range card I am talking about. Hard data. I laminate these for my data book. I run the Gun MPH as an experienced shooter but, sometimes I want to double check or verify the hold, ergo, the data chart. In the end its another tool in the tool kit. You'll need to define and build your tool kit for what works for you and your shooting level.

 

[_Windrider_]

This is the best question. Thank you
This discipline/purpose of this is pointed at newer shooters. Maybe someone who does not grasp the gun MPH method yet. Think "day 2" of shooting. Once the Gun MPH is figured out its what I recommend because its so fast. But for new shooters in a low stress environment, with one target, that have time to study and figure out the wind using 6-8-10 gives them the most options for the best result. Maybe its a shooter that is learning to read the wind and work on thier wind process. Some shooters never grasp the Gun MPH method. (yearly hunter that shoots 20 rounds a year and stays within 400yds)


Honest questions: Why would you write this down?
Its meant to be memorized and fast action. I used to do this too but then asked myself why and decided to stop writing down what I already know.


Agreed on both of these points. An advanced shooter can manage the wind changes and the gun MPH. Not all long range shooters will be able to do this, that's who this is pointed at.


If you used these together it might work, I had not analyzed this option. But to get 18mph wind i'd have to do (10mph hold x 2) - (1mph hold x 2) This could be a good option to reduce the rounding error and be somewhat speedy. I still think (6mph hold x 3) is faster and less brain work., but maybe its a personal preference.

-----------------------------------
Here is an example of the range card I am talking about. Hard data. I laminate these for my data book. I run the Gun MPH as an experienced shooter but, sometimes I want to double check or verify the hold, ergo, the data chart. In the end its another tool in the tool kit. You'll need to define and build your tool kit for what works for you and your shooting level.

View attachment 7807568

Yes 6x3 is faster. Only one calculation. Perhaps mine is fast for the primes. Couple ways to skin this cat but I like that we are evolving and refining and sharing.

 

[SonoranPrecision]

This is the best question. Thank you
This discipline/purpose of this is pointed at newer shooters. Maybe someone who does not grasp the gun MPH method yet. Think "day 2" of shooting. Once the Gun MPH is figured out its what I recommend because its so fast. But for new shooters in a low stress environment, with one target, that have time to study and figure out the wind using 6-8-10 gives them the most options for the best result. Maybe its a shooter that is learning to read the wind and work on thier wind process. Some shooters never grasp the Gun MPH method. (yearly hunter that shoots 20 rounds a year and stays within 400yds)


Honest questions: Why would you write this down?
Its meant to be memorized and fast action. I used to do this too but then asked myself why and decided to stop writing down what I already know.


Agreed on both of these points. An advanced shooter can manage the wind changes and the gun MPH. Not all long range shooters will be able to do this, that's who this is pointed at.


If you used these together it might work, I had not analyzed this option. But to get 18mph wind i'd have to do (10mph hold x 2) - (1mph hold x 2) This could be a good option to reduce the rounding error and be somewhat speedy. I still think (6mph hold x 3) is faster and less brain work., but maybe its a personal preference.

-----------------------------------
Here is an example of the range card I am talking about. Hard data. I laminate these for my data book. I run the Gun MPH as an experienced shooter but, sometimes I want to double check or verify the hold, ergo, the data chart. In the end its another tool in the tool kit. You'll need to define and build your tool kit for what works for you and your shooting level.

View attachment 7807568

I like having (and do have) redundancies as much as the next guy.

But with less experienced shooters in mind, I still think taking the time to explain the concept of gun mph is the simplest way for them to get going with wind reading.

I think it’s much easier to say, you have a 5 mph gun. If the wind is 5mph, you have a .3 mil hold at 300, .4 at 400, .5 at 500. If the wind is 10 mph, double the wind hold. As long as they aren’t shooting exceedingly small targets, this will work fine as they build experience and confidence.

The other thing this does, is it prevents them from starting to think of wind as a set of equations.

For instance, shooter A says to himself, “this is a 14mph wind, so use the 6 and 8 mph winds to figure out 7, then multiply that wind by 2.”

Meanwhile the shooter B say to himself, “14 is about 15. Gun number times 3.” And he gets an impact while

Then if you want to have something written down, you just write the gun mph in case you forget.

If wind was as predictable as gravity, I’d be all over the 3 numbers thing. OR if the shooter is using MOA, as the gun number thing is not as clean in that instance.

 

[Makinchips208]

I agree with the numbers on your charts and, makes sense. You have lots of experience training people, so I see you having another method, and can appreciate the time you invested to establish this math and charts! As I imagine not everyone gets the gun mph method.
Is wind probably one of the hardest things for new shooters to comprehend?

 

[dilantutor]

The best wind speeds to put into the printed data chart are 5, 10 and 15 miles per hour.

This is because these are the most common wind speeds in the United States.

 

[Jack Master]

The best wind speeds to put into the printed data chart are 5, 10 and 15 miles per hour.

This is because these are the most common wind speeds in the United States.

That how fast they program the wind turbin fans to go.

 

[TheOtherAndrew]

If your going to use intervals of 2mph why not just use 2mph and have 1 number per yardage instead of 3 - since you already HAVE to do some kind of mental math (angle)?

Really the answer to me depends on your expected accuracy (Kraft-like drills) and expected target size. If youre planning on shooting eggs to 1000yd and you have a <MOA gun (shooter+gun at more than just 100yd) then you might as well just have an entire page of possible wind holds; next level would be to just rely solely on Kestrel - you'll probably miss first shot.

If your gun+shooter = 1.5-2MOA and you know no targets will be <MOA then my math (regarding my gun at least) says you can have ~3(3.4mph) of error and still expect to hit reasonably often 0.5-1.0s TOF (400/700yd). If FVwinds are under 10mph and inside 1s TOF you just hold edge (closer distances) or just off edge plate (further distances).

What can get you most IMO is shooting multiple targets with a spread >20deg. In these situations and with time as a stressor you better have a better wind management plan than reading off your sheet of paper or trying to do hard mental math (T1-18*1/4 for 450y...T2-18*3/4 for 650y).

But if you are a newer shooter then time stress isn't a thing yet and looking at any sort of data table (1/10, 4/6/8, full blown wind sheet unto itself in 3mph interval with diff values) is awesome for learning, seeing patterns, etc.

por ejemplo:

*question: if higher DA changes your bullets (vertical) trajectory, doesn't it stand to reason it'd have some effect on (horizontal) trajectory - wind - too (much less, but still if you know how pressure/DA works at its core you know its thick air vs thin so do the math exercise and figure out WHEN you should expect a change in your gunMPH)?

 

[Coyote-6]

Man I fucking love this OP! You have to be an engineer, since you've overcomplicated it to the n'th degree, but I like you challenging the standard.

Your numbers and methods will work for the highest of 1 mph increments up to 26ish mph. I will confirm that (like the illustrated charts btw).

However, I think for MOST, it's too much to go through when lowlights standard mph rule will work just as well with less stuff on the page. Especially if you have a 5mph gun.

I am a data-whore (which it sounds like you are too) but find myself having to hold back to the simplest terms when running a rifle, especially in a firefight or competitive stage. KISS rules the world in those arenas.

 

[TheOtherAndrew]

Wind Call - RAGS/10A

6mph Gun# values Multiply value most resembling actual wind speed and angle by range to target and you have your wind solution!

www.snipershide.com