Mile Shot

[bigngreen]

Your correct that in the amount of wind drift will be higher at lower bullet velocities BUT when you take into account the amount of time the bullet travels on the path set by the early wind it is a greater value because it has agreater time to travel. So a .4 in windage movement at the first 100 yards over the course of 1500 yards is much greater in the end that a 2 inch move at the last 100 yards. Yes the last deflected more but over the time of flight the close range adds more total value.

 

[Truc]

Don't know about out west but here on the east coast the wind can actually be blowing from 3 different directions in as little as 200 yds. I have never seen wind as a constant, it picks up, drops off, reverses up and down the range. Then you add rain to it and I have to say **** good shooting

 

[steeltraps]

Same in north alabama. I can shoot 1800 yards in big cornfeild surronded by mountains. Topography is bottom land/coves mountains. I have wind flags every 500 yards out to 1800 yards. Some times every flag , like you said is doing something differnt! Thats when i just throw a 300 gr otm berger down their and see where it hits then make my wind call of that hit!gun)

 

[WildRose]

Your correct that in the amount of wind drift will be higher at lower bullet velocities BUT when you take into account the amount of time the bullet travels on the path set by the early wind it is a greater value because it has agreater time to travel. So a .4 in windage movement at the first 100 yards over the course of 1500 yards is much greater in the end that a 2 inch move at the last 100 yards. Yes the last deflected more but over the time of flight the close range adds more total value.

I understand your thinking but it's not correct.

You are thinking in terms of how an error at 100yds increases in value as the distance grows.

Deviations due to an error at the muzzle increase linearly.

If you are off 1" at 100, the error would then be 10" at one thousand. The deviation from LOS in this case is linear.

Looking at wind effect on the bullet however is not linear because you have a constant force acting against the bullet throughout it's flight and the effect of that force becomes greater per measured range increment due to the slowing of the bullet.

Look at wind effects on flight similar to gravity. Neither are linear, it's a curve with an ever greater effect throughout the flight of the bullet.

 

[ccsykes]

Wildrose, you are correct sir, it follows a one-sided parabolic curve. Look at the same bullet moving two different speeds, deflection is greater with the slower projectile with constant atmospheric conditions across the experiment. Yes a deviation at 100 yards impacts the location of a projectile striking a target more at 1200 yards than the same deviation from the bullet's 1000 yard position, i.e. a 1 MOA deviation at each distance.

So physically it is correct to say a similar deviation closer to the muzzle as opposed to farther away will have a greater net result on the impact from center of target. But at the same time the projectile slows farther from the muzzle and is therefore affected more by lateral forces.

By the way, it took 11 MOA at 1760 and I was still 5" right of center.

 

[WildRose]

Wildrose, you are correct sir, it follows a one-sided parabolic curve. Look at the same bullet moving two different speeds, deflection is greater with the slower projectile with constant atmospheric conditions across the experiment. Yes a deviation at 100 yards impacts the location of a projectile striking a target more at 1200 yards than the same deviation from the bullet's 1000 yard position, i.e. a 1 MOA deviation at each distance.

So physically it is correct to say a similar deviation closer to the muzzle as opposed to farther away will have a greater net result on the impact from center of target. But at the same time the projectile slows farther from the muzzle and is therefore affected more by lateral forces.

By the way, it took 11 MOA at 1760 and I was still 5" right of center.

Dude at that range 5" is a rounding error LOL Just hitting the damned thing was a tremendous accomplishment.

That would have still been a killing shot on a coyote at 1 mile!

 

[bigngreen]

I understand your thinking but it's not correct.

You are thinking in terms of how an error at 100yds increases in value as the distance grows.

Deviations due to an error at the muzzle increase linearly.

If you are off 1" at 100, the error would then be 10" at one thousand. The deviation from LOS in this case is linear.

Looking at wind effect on the bullet however is not linear because you have a constant force acting against the bullet throughout it's flight and the effect of that force becomes greater per measured range increment due to the slowing of the bullet.

Look at wind effects on flight similar to gravity. Neither are linear, it's a curve with an ever greater effect throughout the flight of the bullet.

Unfortunately it's not my thinking, those number are directly from a ballistics program, look at what I did, I took the near wind of 10 mph for 500 yards then told the program the wind from 500 to 1500 was zero and this shows you the effect of that 500 yards of wind in the 1500 yard total. I did the same thing for all three ranges inputting only a 10 mph wind for that segment and it show what just that range contributes to the total at 1500 yards.

If it was not correct then my total of each individual range would not be the same as just using a single wind from 0-1500 yards which it is.

If we look the first 100 yards I had .3 inches of wind drift, if I turn the wind off till 1400 yards then turn in on in the last 100 yards to 1500 it shows a drift of .6 inches so in that respect the bullet is affected more BUT your first wind of .3 over the course of 1500 yards is 8.1 inches. So first 100 yards adds 8.1 inches of wind drift at 1500 and the last 100 yards only adds .6 inches, which is greater? Again not my thinking, it's the ballistic program doing the calculation with zero interpretation from me.

The wind in the first half of your trajectory is the major player!

 

[WildRose]

Unfortunately it's not my thinking, those number are directly from a ballistics program, look at what I did, I took the near wind of 10 mph for 500 yards then told the program the wind from 500 to 1500 was zero and this shows you the effect of that 500 yards of wind in the 1500 yard total. I did the same thing for all three ranges inputting only a 10 mph wind for that segment and it show what just that range contributes to the total at 1500 yards.

If it was not correct then my total of each individual range would not be the same as just using a single wind from 0-1500 yards which it is.

If we look the first 100 yards I had .3 inches of wind drift, if I turn the wind off till 1400 yards then turn in on in the last 100 yards to 1500 it shows a drift of .6 inches so in that respect the bullet is affected more BUT your first wind of .3 over the course of 1500 yards is 8.1 inches. So first 100 yards adds 8.1 inches of wind drift at 1500 and the last 100 yards only adds .6 inches, which is greater? Again not my thinking, it's the ballistic program doing the calculation with zero interpretation from me.

The wind in the first half of your trajectory is the major player!

I'm sorry you are simply wrong.

I gave it to you in 100yds increments all the way to 1500 in INCHES, and the rate of deviation for each of those increments grows because for each of them the bullet takes longer to cover with the same steady force acting against it. The slower it gets the more the wind has time to work on it and thus greater deviation from LOS/POA.

 

[bigngreen]

I'm sorry you are simply wrong.

I gave it to you in 100yds increments all the way to 1500 in INCHES, and the rate of deviation for each of those increments grows because for each of them the bullet takes longer to cover with the same steady force acting against it. The slower it gets the more the wind has time to work on it and thus greater deviation from LOS/POA.

I'm just using a ballistics engine and telling you the solution your not going to be able to removed the previous winds influence without a multiple wind program.

Read this again, directly from Patagoinia Ballistics Coldbore, I tell it I have a 10 mph wind for ONLY the first 100 yards and then a zero wind it calculates that at 1500 yards it would cause 8.1 inches of wind drift.
If I zero the wind till 1400 yards then put it to 10 mph it tells me that from 1400 yards to 1500 yards there is .6 inches of wind drift.

Those are the facts from a top end ballistic solver that allows three different wind values not from me, if you have access to a ballistic solver that will allow you to set ranges and values to a wind you will see the exact same thing as I am.
So which is greater 8.1 inches or .6 inches?

 

[WildRose]

I'm just using a ballistics engine and telling you the solution your not going to be able to removed the previous winds influence without a multiple wind program.

Read this again, directly from Patagoinia Ballistics Coldbore, I tell it I have a 10 mph wind for ONLY the first 100 yards and then a zero wind it calculates that at 1500 yards it would cause 8.1 inches of wind drift.
If I zero the wind till 1400 yards then put it to 10 mph it tells me that from 1400 yards to 1500 yards there is .6 inches of wind drift.

Those are the facts from a top end ballistic solver that allows three different wind values not from me, if you have access to a ballistic solver that will allow you to set ranges and values to a wind you will see the exact same thing as I am.
So which is greater 8.1 inches or .6 inches?

I provided a link to the engine used and gave you the details plugged in, and then provided you at 100yds increments the change from POA.

As velocity decays deviation per 100yds increases because the steady force of the wind is acting constantly against it similar to gravity and as I showed nearly 2/3 of the total deviation occurs in the last 500yds.

This is why the windage deviation is a curve, not a straight line

 

[vinson]

You are both right and the reality is somewhere in between what you two describe.

WildRose, since (I assume) we can agree that a rifle capable of shooting exactly 1" 100 round groups at 100 yards and given perfect conditions (zero wind, solid rest, no ammo or shooter variance, etc) can shoot 10" 100 round groups at 1000 yards (with proper DOPE) we can demonstrate that a bullet passing directly into our 100 yard point of aim would have hit directly in the center of our 1000 yard point of aim. However the bullet that would have landed 1/2" left of our 100 yard POI would have landed 5" left of our POI at 1000.

Thus the effects of displacement on a bullet early on do of course have effects downrange. The bullet will continue on its deviated path and from 500 yards to 1000 will have (approximately) doubled in deviation given no more external inputs such as wind.

Bigngreen, what your segmented calculation demonstrates is not that the 0-500 wind is acting more on the bullet, that is definitely false, but since the bullet has that additional 500 or 1000 yards to continue on its deviated path it will and thus the apparent effect is larger at longer distances. It's not that the wind is pushing the slower bullet less at 500-1000 yards or 1000-1500 yards, its merely that the effects of that push have less time to compound. To support your main claim your calculation would have needed to only use 0-500 yards and show that the 10mph wind affected a faster FPS bullet more.

Thank you two for the opportunity to think about this and actually improve my thinking of the effects of wind on a bullet.

Vinson

 

[bigngreen]

I provided a link to the engine used and gave you the details plugged in, and then provided you at 100yds increments the change from POA.

As velocity decays deviation per 100yds increases because the steady force of the wind is acting constantly against it similar to gravity and as I showed nearly 2/3 of the total deviation occurs in the last 500yds.

This is why the windage deviation is a curve, not a straight line

Look at my numbers, if I was giving numbers based on a straight line the wind drift at 1500 yards for the first 100 yards would have been 4.5 inches NOT the 8.1 inches the ballistics program calculates!

I fully understand and showed you the numbers that the the wind pushes the bullet farther the last 100 yards by double, .3 inches for the first hundred and .6 for the last hundred.
When you cut of the first 1000 yards of wind drift you've removed the cumulative total only to that point, but you have not removed the value of the trajectory it's continuing on based on that first 1000 yards so what your looking at for your last 500 is the effect of the last 500 yards of wind PLUS the trajectory that is is on based on the first 1000 yards!!!

 

[bigngreen]

Lets use your ballistics calculator, I put my number into it and it gave me a wind drift of 83.2 inches at 1500 yard and mine give me 81.4 but they are within 2 inches which is close enough for us I would think. So both programs track perfectly and giving the same correction.

Now I will simply simulate in mine a bad wind call, yours won't do it because it's not capable of showing you different wind speeds and ranges but since we established that they track about dead nuts it should be believable any data mine give yours would also if it was capable.

A 10 MPH wind from 0-1500 yards give us a correction of 81.4 inches, this is our baseline.

First lets miss the wind call for the last 500 yards of the trajectory and the wind dropped to zero (using zero just makes it easier to see) I set my wind to 10 mph from 0-1000 yards and 0 mph from 1000 to 1500 yards and the correction at 1500 should have been 68.4 inches.

Now lets miss our wind call for the first 500 yards so I set my first 500 yards to zero wind and my last 1000 to 10 mph in my program and it gives me a correction at 1500 yards of 43 inches.

So if I miss my FAR call by 10 mph I only miss by 13 inches by missing my NEAR wind call by 10 mph I missed by 38.4.

These numbers are from my calculator that I established earlier tracked with yours within 2 inches at 1500 yards!

Here is a graph, track three in yellow is a wind of 10 mph to 1500 yards. Track 2 in orange is nailing the wind till the last third of the trajectory and track 1 in red is missing your wind call on the first third of the trajectory but nailing it on the last 2/3rds. You will hit closer to your point of aim if you miss the wind call on the last third vs missing the wind call on the first third.

 

[dkhunt14]

Maybe all you people that didn't believe me about cheek contact should go to 6BR accurate shooter.com and read the Daily Bulletin Richard Kings Radical f-Class Rig. Instead of calling HORSESCHITT and April Fools. Benchresters get used to it from the ground layers. Must be some kind of jealousy. There is more then one reason to do it. The heat mirage from the barrel and inconsistencies from the stock dragging can effect accuracy. But you have to remove all parallax from the scope which should be done any how. Matt