Effect of Wind on Pellet

[thomasair]

More in depth info about aerodynamic jump.

Vertical Deflection For Pellets In Crosswind - Hard Air Magazine

This month Bob Sterne reveals some surprising information about what happens to airgun pellets in crosswind. You may need to read this more than once…

hardairmagazine.com

 

[L.Leon]

I was going to leave this thread. And well, I got to thinking about it.
Seeing as how I rattled the hornets nest.
I wanted to apologize to you guys for my forum demeanor. Sometimes I type and wish I could go back and revise my thoughts , but by that time the horse has already left the barn.
Some valid points have been made here. Aerodynamic jump for instance. Which cannot be fully accounted for, at all. It will/could/might get you closer. Sometimes a lot closer. But not every time. The effects of wind are the effects of turbulence , which can change every 1 yard , or less, down the range. It changes a lot as the right hand twisted projectile travels 50-100 yards down range.
Anyways, I didn't mean to come off as combative.
You guys , be well.

Nothing to be forgiven for… You were being passionate…

 

[AlwaysLastPlace]

The chart works but you also need to understand the wind may change along the flight path of the pellet or between when you checked it and when the pellet flew. When it varies along the path you need multiple wind flags to even see what is happening.

I do not remember why but the ballistic coefficient has a lot to do with wind drift. Pellets have low bc so they drift a lot. I've played with chairgun some to see the potential drift of different wind speeds and different pellets.

I would love to hear if a shooter has seen left wind close and right wind far and if he just holds dead on.

 

[thomasair]

I would love to hear if a shooter has seen left wind close and right wind far and if he just holds dead on.

Yes

 

[cavedweller]

Nervoustrig, I am unable to print the wind charts in your posting, do you have a Word or PDF file you could provide? Thanks, Tom

So ok. You guys win! The chart is the Holy Grail, when it comes to TURBULENCE. Even after someone just admitted that he misses. while using the chart.
But it made him a better shooter.
You can't make this stuff up. But someone did. And its gone on for too long.

 

[JackHughs]

They differ.

Bullets:
View attachment 522883

Pellets:
View attachment 522884

Over the years, I've shot competitively and served as match director for military benchrest, Cast Bullet Association, American Single Shot Rifle Association, International Single Shot Association, IR 50-50, and the American Rimfire Association. Every shooter I've been acquainted with was aware of the wind chart. No shooter in my acquaintance ever relied on the wind chart as the basis for a shot.

The reason for this is that the chart is based on ideal conditions and we never shoot in truly ideal conditions. We rely on our ability to read and understand our particular down range wind indicators and our ability to place those indicators to best advantage depending on the physical characteristics of the range.

The buildings, walls, backstops, and baffles on my home range all conspire to cause substantial updrafts and downdrafts - particularly on our 50-100 yard range. These updrafts and downdrafts have the same effect on a spinning projectile as does a crosswind operating over a similar period of time. The chart does not take updrafts and downdrafts into account.

So, at least in my experience, the wind chart is interesting but is no substitute for one's ability to recognize, read, and understand ever changing wind patterns in real time.

JackHughs

 

[Troy Bakel]

@AlwaysLastPlace

Deconstructing Mike's "Yes".

Mike’s answer is honest but a "Left wind close and a right wind far" means little.

When Mike looks down range he looks at both where each flag is pointed and the position of each flag's ribbon.

He knows that wind direction and speed close to the muzzle establishes the initial trajectory of the projectile and wind direction and speed has less affect closer to the target.

He also chooses a projectile he knows flies good for the range conditions he has been evaluating as he set up his bench

So let's assume a 50 yard shot and he has a 90° push left close to the muzzle with the tail fluttering at 10° off the deck and a 40° push right at 40 yards with the tail fluttering at between 40° and 60° off the deck.

Based on the knowledge he has gained from launching his choosen round more than a thousand times he may place the crosshair dot on the dead center of the target X dot, shift the crosshair dot two paper threads left and send it. And throw a hard 10X.

When I practice Precision Benchrest I set up next to an individual who like Mike enjoys the wind and has sent thousands of rounds down range and would answer your exact question the same way - with a simple "Yes".

Then you try it and throw a hard 8 at 10 o'clock.

 

[thomasair]

Nobody successful looks down range and says.....gee, it looks like a full value left to right wind. Let's have a look at the chart so I can tell where to hold.

The value of the chart...as I've already stated, is so people can understand that aerodynamic jump is a factor in figuring out the most successful place to hold based on the conditions they can see in the flags. Do I literally have the chart on hand so I can tell what to do? No, but I know what the effects of aerodynamic jump are and how it most likely will apply....and those effects are pointed out on the chart in their most basic form.

Mike

 

[thomasair]

@AlwaysLastPlace

Deconstructing Mike's "Yes".

Mike’s answer is honest but a "Left wind close and a right wind far" means little.

When Mike looks down range he looks at both where each flag is pointed and the position of each flags ribbon.

He knows that wind direction and speed close to the muzzle establishes the initial trajectory of the projectile and wind direction and speed has less affect closer to the target.

He also chooses a projectile he knows flies good for the range conditions he has been evaluating as he set up his bench

So let's assume a 50 yard shot and he has a 90° push left close to the muzzle with the tail fluttering at 10° off the deck and a 40° push right at 40 yards with the tail fluttering at between 40° and 60° off the deck.

Based on the knowledge he has gained from launching his choosen round more than a thousand times he may place the crosshair dot on the X dot, shift the crosshair dot two paper threads left and send it.

When I practice Precision Benchrest I set up next to an individual who like Mike enjoys the wind and has sent thousands of rounds down range and would answer your question the same way - with a simple "Yes".

Then you try it and throw a hard 8 at 10 o'clock.

I place my 3 wind flags at ranges that represent an equal zone of influence. This means that my first flag is pretty close to the bench and covers a smallish zone. The second flag covers a bigger zone, and the third even bigger yet. This means that if my first flag is going the opposite way of my last 2....my mathematically calculated hold will be 1/3 less than what the tails are telling me the wind velocity is.

The zones for each flag were determined with a ballistic program. I've explained all of this in another thread somewhere so I won't try to fully repeat it.

I cannot use much more information than three flags can provide ...so that's what I use.

What I do works for me. Most do it differently. Most have a hard time beating me, though.

 

[Troy Bakel]

Over the years, I've shot competitively and served as match director for military benchrest, Cast Bullet Association, American Single Shot Rifle Association, International Single Shot Association, IR 50-50, and the American Rimfire Association. Every shooter I've been acquainted with was aware of the wind chart. No shooter in my acquaintance ever relied on the wind chart as the basis for a shot.

The reason for this is that the chart is based on ideal conditions and we never shoot in truly ideal conditions. We rely on our ability to read and understand our particular down range wind indicators and our ability to place those indicators to best advantage depending on the physical characteristics of the range.

The buildings, walls, backstops, and baffles on my home range all conspire to cause substantial updrafts and downdrafts - particularly on our 50-100 yard range. These updrafts and downdrafts have the same effect on a spinning projectile as does a crosswind operating over a similar period of time. The chart does not take updrafts and downdrafts into account.

So, at least in my experience, the wind chart is interesting but is no substitute for one's ability to recognize, read, and understand ever changing wind patterns in real time.

JackHughs

On Palmyra Sportsmens Association's Competition Rifle Range , I cheat. On our weekend practice shoots I set my bench up at position 1 or 2 so I can shoot right down the wall. Normally the wind is moving from right to left above my target, left to right below my target and the mirage is bubbling upwards across my target.

As long as the Windicator at 3 yards is hanging straight down and the mirage is bubbling I can send my < 12 fpe 9.57 grain round nose diabolo 20 yards down that vortex and throw 10s. While everyone to my right are:

 

[Troy Bakel]

I place my 3 wind flags at ranges that represent an equal zone of influence. This means that my first flag is pretty close to the bench and covers a smallish zone. The second flag covers a bigger zone, and the third even bigger yet. This means that if my first flag is going the opposite way of my last 2....my mathematically calculated hold will be 1/3 less than what the tails are telling me the wind velocity is.

The zones for each flag were determined with a ballistic program. I've explained all of this in another thread somewhere so I won't try to fully repeat it.

I cannot use much more information than three flags can provide ...so that's what I use.

What I do works for me. Most do it differently. Most have a hard time beating me, though.

I shoot just 20 yards with my < 12 fpe Thomas BR and all I use is a Windicator and two flags each with tails.

I look to my right and see the flags used by those shooting 100 yards and my brain fries.

Now I did test out to 60 yards with flag placement and found that once my 3 different pellets drop past their apex the wind really had an affect, more so than that at the muzzle.

So I moved back to 20 yards and set all three indicators below the muzzle height and directly in line with the target. The Windicator is always at 3 yards, the two flags very depending on wind conditions but none further than 15 yards.

Depending on the Windicator and flag movement I will use a 7.0 grain wad cutter, an 8.0 grain wad cutter, or a 9.57 grain domed diabolo.

I am getting experienced enough now to vary pellets on the same card as range conditions change.

I would be totally lost on a different range.

P.S. Thanks again for all the information you have passed my way.

 

[coastal drifter]

I think all the experts here took the wind chart to literal, I believe it was just meant to give a little basic understanding of "wind reading" for the newer shooters. Heck even I know it's not a 100 in every wind condition, hopefully it will help get you in the ballpark so you might be able to adjust the next shot.
As the saying goes, practice makes perfect or at least better.

 

[Ballisticboy]

I think all the experts here took the wind chart to literal, I believe it was just meant to give a little basic understanding of "wind reading" for the newer shooters. Heck even I know it's not a 100 in every wind condition, hopefully it will help get you in the ballpark so you might be able to adjust the next shot.
As the saying goes, practice makes perfect or at least better.

Exactly this, the chart is only meant to help you understand the total effects of wind from the different directions, not to predict the exact wind deflections on any given day at any point on the earth.

Some people seem to resist having anything which can help with basic understanding on anything to do with pellets and slugs, preferring to rely on myth and magic and performing fixed rituals whenever they go shooting.

 

[TomJ]

Ballisticsboy, do you have a pdf or Word file for the pellet version of the wind chart. For whatever reason, I cannot print from a screenshot or download a copy, the POI and POA print the target does not . I’d like to have one to refer to on the lid of my shooting box. This has been a great discussion. Thanks, Tom

 

[SilentSquirrel]

Ballisticsboy, do you have a pdf or Word file for the pellet version of the wind chart. For whatever reason, I cannot print from a screenshot or download a copy, the POI and POA print the target does not . I’d like to have one to refer to on the lid of my shooting box. This has been a great discussion. Thanks, Tom

Tom
Perhaps this will print for you

Edward

View attachment Wind & pellets.pdf

 

[dennisu]

Mike

You mentioned that you setup your zones for each flag with a ballistics program. Which one are you using?

Dennis

 

[thomasair]

I used Chairgun...but it doesn't have an actual feature that is made to do this.

Here are the distances I use.

Flag spacing for 2 flags 25m
13 ft
54 ft

2 flags for 50y
25, 100

3 flags for 50y
15, 50, 110

 

[dennisu]

I use Chairgun as well. Thanks for providing the distances you use.

 

[bigHUN]

I had couple of these charts from the past. Not sure from where the contrast is coming from

vs....

And this one for bullets

 

[thomasair]

That's what happens when people post things that they actually don't have any experience with. It's all too common, unfortunately.