Do windflags lie?

About the .5 mph wind moving a bullet.....

I would yes, most ceratinly, not much, but still yes.

To use an analogy not far from beua's (bears crap in the woods, not the range):D

If a car is going down the road and the road moves left 20 feet the car moves left 20 feet. The road is the medium carrying the car. The air is medium carrying the bullet.



On a different note, if the car is traveling at the speed of light and turns on its headlights, what happens???
 
sailor said:
Ok, new shooter chiming in here. Is it a myth that a puff of wind in the first 10 yards will move the point of impact more than a puff in the last ten yards?
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Hello Sailor
It’s true and can make your eyes water too, but I try and identify which shooter the wind is coming from and sit at least 10m up breeze from them.

Peter
 
HuskerP7M8 said:
Dan,

I use Professor Art Pejsa’s software for my research and testing with projectiles in the transonic range of velocities and to the best of my knowledge it’s the most accurate available for this purpose.

Using a ballistic coefficient in the .15 to .16 range which is close to what McCoy observed at the Ballistic Research Laboratory with Eley and RWS round nose bullets shows a wind deflection of 0.04” at 50 yds for a .5mph wind.

Landy
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Landy,

How do you explain shooting when the conditions are "dead calm" and bullets don't go where they're supposed to? Case in point: shoot with all flags pointed at three o'clock, dead air, tails hanging straight down. Now let the flags turn to nine o'clock tails straight down. Point of impact will be one full ring to the right. Dead calm, don't believe it. If I'm not mistaken that would be .125", with no wind. Don't know why, but, you do have to adjust your hold.

Ken
 
Ken,

Sorry, but I can’t provide an explanation for that much movement under the conditions you describe….not from a ballistics standpoint anyway.

Let’s try approaching this anomalous projectile behavior from another perspective: That being the normal random dispersion inherent in all shot groupings with rimfires.

First, you have to agree that there is not a rimfire in existence capable of placing every shot thru the same hole. You may be able to fire a short series of shots where random chance allows you to do it but when you fire a longer series of shots such as you would at a BR target….the group becomes quite large.
How large you say….well based on only a partial analysis of the scores being fired indoors where conditions are most conducive for determining the rifles capabilities vs the shooter’s ability, I can make an educated guess or rough estimate of maybe 0.300” give or take a few hundredths.
Without troubling with a mathematical analysis or using the GAP software, I would think we’d see a lot more IR 50/50 250 25x’s (0.255” 25 shot group size), ARA 2500’s (0.276” 25 shot group size), and PSL 2500’s (0.283” 25 shot group size) if anybody has rifles consistently shooting better than the 0.300” range. We do seem to see many more USBR 250’s (0.324” 25 shot group size).

Please let me know if my measurements are incorrect or if my thoughts on scores are erroneous because those are the numbers I’m using for my rough estimate.

Anyway, I think that any shot within the .3” to .5” range (depends on your rifle’s accuracy) might be declared a flyer or attributed to some unseen force, but, may just be simply an outlier from the boundaries of the density pattern/grouping normally formed by “your” rifle.

If you’re curious about what I typically see with my firearms with the methods I’ve developed and the GAP software….you could look at my blog.
BTW, I’m just another one of those internet “expurts” and there are thousands of them….so your mileage may vary.

Landy
 
Ken, in testing a new probe that I built, when the flags are motionless, the probe will actually pick up puffs of wind that will show an equal deflection to what a steady 3 mph shows. The tails and props never see these puffs and if that is usually what is happening in what we are used to knowing as a calm condition, then no wonder the accuracy goes to pot.
 
HuskerP7M8 said:
Let’s try approaching this anomalous projectile behavior from another perspective: That being the normal random dispersion inherent in all shot groupings with rimfires.Landy
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That will not explain why my AGBR rifle shows the exact same behaviour under the 'calm' condition. Even at 25 yds and with 4 ultra sensitive flags you don't have any idea where the pellet is going if the flags are showing a dead calm.
 
crb said:
That will not explain why my AGBR rifle shows the exact same behaviour under the 'calm' condition. Even at 25 yds and with 4 ultra sensitive flags you don't have any idea where the pellet is going if the flags are showing a dead calm.
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There must be some confusion on your part or mine.
The way I understand your statement….you’re proving my contention.
Let me know.

Landy
 
I think you may be right about the confusion. There is NO WAY I think that the wind makes my gun capable of better groups and in a genuine dead calm [ as in a tunnel ]that it will naturally shoot big groups. If that is your contention then you are definitely right about the confusion.
 
crb said:
I think you may be right about the confusion. There is NO WAY I think that the wind makes my gun capable of better groups and in a genuine dead calm [ as in a tunnel ]that it will naturally shoot big groups. If that is your contention then you are definitely right about the confusion.
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We agree then.:D
 
I must disagree that the most effect of the bullet movement is that of the forst 10 or so yards, this is brought to light as the bullet is most effected by the wind in the slowest speed throughout the course, that said the wind at the target has the most effect due to the slowest speed of the bullet.

There are residual wind conditions that must be considered also, these are when the wind comes OFF from a value and falls the flaggs one needas to be careful to wait until all the aforementioned wind is gone.

Clarence
 
cdupuy
The wind has the most effect when the bullet is slowing down the most and that is in the first 0 to 15 yds. Not when the bullet is going the slowest.
Fred K
 
reading the wind

I think I have found out due to wind probe why on a calm day that for the most part there is usualy a steady wind blowing allthough my body does not detact the wind. So it is very important to use probe more closley then on a gusty or hard wind day. I think on a calm day we doin't pay close attention when we should pay closer attention.
BOER
 
You all can shoot groups all you want. have itsy-bitsy ones or large ones. But can you actually PREDICT where a bullet will impact on a score target? The wind effects the bullet, but, is it predictable? If it isn't then your gun is not in tune and/or you are forgetting the largest part of the paradox. If your gun is predictable in the calm can it predictably shoot in the wind?

Carp
 
Fred we could argue this all day, however have you ever shot the 1000yd matches? I never watch the closest flag except for direction.

Clarence
 
1,000 vs 50

That may be true for 1,000 yards, but this is 50 yards we're talking about.
They are all important, so take a few extra sighters as the flags move around, and then make up your mind as to which condition you like the best.
 
Landy,

I can't explain why a bullet will drift that much in dead air either. But it's there and it's real. Another problem with dead calm is layered air or thermals. Can't see them on the flags, but they can affect the flight path of the bullet. Don't blame the rifle, most of the rifles we use are capable of very small groups. If you don't see a conditon change, or don't recognize it, not the rifle's fault.

Ken
 
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