Wind, and groupings.

[rangur1]

Just got through embarrassing myself again at 100 yards shooting groups. Now I feel wind plays a serious factor, especially swirling winds that change direction often. Even at low levels, about 4-6 mph. Now I was consistently shooting 3/4” 5 shot groups at 50 yards. Best being 1/2” group. But at 100 yards? 3” to 3.25” . This has usually been 3 within an inch 1 about 3/4” away from them and the last more than 1.5 inches from any others. Would those wind conditions affect 40-42 grain slugs like that? Because if you do a straight extrapolation, my groups should only expand to 1-1.5” even with my limited skill. The 50 yard results appear to back that.

 

[elh0102]

I think you will find that wind, as with most variables, does not have a linear relationship to your groups or scores. A heavier slug, shot from a well matched barrel, would probably be influenced less by that wind condition, but it might not be what you would expect. As always, shoot and see.

 

[beerthief]

fifty yards is a lot of opportunity for the wind to play havoc . even shooting high power .
There was an FT lane that had a creek that crossed the lane just before the target @ 55 yards , played hell with everybody .

 

[JimNM]

The air/wind does not act as monolithic block. It swirls, lifts, drops and shears constantly. One way to visualize the wind current is to use kid's bubble solution. Blow a string of bubbles and watch how each bubble moves in different directions and at different rates. From bubble to bubble the wind effect is different.

Have you ever swam or floated in a river? I floated some gentle rapids on my honeymoon in a life vest. The multitude of directions that I felt from the water still sticks in my memory today. Water is some 47 times more dense that air, but the effect is similar.

 

[jps2486]

The wind can do strange things that make you say: "WTF?"

 

[rangur1]

Yes, excellent replies. I understand wind is not monolithic. In a wind free environment my extrapolation would be accurate. My question was will the swirling wind cause my observed effects. The answer appears to be a huge yes. That’s what I wanted to confirm. Thanks.

 

[JimD]

I sometimes play with wind speed in Chairgun to get an idea if it is credible that the wind affected my results. You can input both the wind speed and the direction (and the bc, velocity, etc.) and it will give you the drift. I'm sure other trajectory programs do this.

My best 100 yard groups (5 shot) were just over 2 inches. That was with a 22 caliber pellet gun shooting it's favorite pellet. It occasionally has put 3 of these pellets into a single hole group at 25 yards - center to center well under .1 inches. I know people have shot smaller but I think 2-3 inches is a more reasonable expectation for most of us.

 

[thomasair]

Wind drift squares with distance....twice the distance equals 4 times the drift.

Mike

 

[Motorhead]

Wind flows like water but to a greater degree when there are environmental disruptive features such as Trees, Hills, Berms, Big rocks or even distant mountains.
Generally the ONLY way to really proof Rife, barrel, projectile & Shooter is in a closed space. Inside range, warehouse, closed tunnel etc ...

You also need to know if as distances grow, does the flight pattern of projectile your shooting start coming apart ( Spirals, wobbles etc .. ) ?
Assuming it is just the wind may very well bite you back as there are other factors in play.

 

[rangur1]

Wind flows like water but to a greater degree when there are environmental disruptive features such as Trees, Hills, Berms, Big rocks or even distant mountains.
Generally the ONLY way to really proof Rife, barrel, projectile & Shooter is in a closed space. Inside range, warehouse, closed tunnel etc ...

You also need to know if as distances grow, does the flight pattern of projectile your shooting start coming apart ( Spirals, wobbles etc .. ) ?
Assuming it is just the wind may very well bite you back as there are other factors in play.

YES! Of course, I forgot to mention this range is in a big sand pit. 40 foot berms on 3 sides. Now I’m seeing the obvious reasons for the spreading of the group. I forgot, it’s been a year and a half since I shot at 100 yards, or 50 for that matter.

 

[manabeknives]

Ever see videos of a giant fog bank moving through the mountains ..it's the best visual i can think of seeing how winds flow

 

[Vana2]

Yeah, plotting trajectory is child's play relative to doping the wind!

I have wind flags every 5 yards on my 55 yard shooting lane - it's not unusual to see every flag pointing in a different direction

My 128 yard lane has no flags (yet, a next winter project) where it crosses the swamp but the cattails are good wind indicators.

Fortunately, most days I can count on a couple of hours of dead calm in the morning and in the evenings when I can do my tuning, testing and shooting groups.

Wind does make shooting more challenging/interesting though. My favorite reactive targets are pieces of Honeycomb cereal suspended on a string to blow around in the wind! Fun stuff!

Cheers!

 

[Ta-Ta Toothie]

When your spinners swing all over, you know it's windy.

 

[SilentSquirrel]

If you are anywhere near a god six
zed body of water. observe small sailboats
Better yet
Take sailing lessons.
This will truly alter your thoughts about wind
Just my too sents
Edward

 

[rangur1]

Ever see videos of a giant fog bank moving through the mountains ..it's the best visual i can think of seeing how winds flow

I see what the issue is. Here is a quick video of the range I’m currently using. Ignore my commentary as I was describing it to my non shooting friend.

 

[Ballisticboy]

On one occasion when I was working, I got the range staff to measure and record the wind speed and direction close to the gun every second for an hour. The graphs below show twenty-second samples taken from the measured data.

The wind instrument was out in the open, away from any obstacles which could cause turbulence. The data shows it is the wind direction which gives a major cause for concern as well as the wind speed, even in the open.

 

[maxtrouble]

I have three wind flags and the target is at 55 yards. It is common to see them all going different directions. I find the wind flag closest to me has the most effect on my shots. I can get pellet on pellet groups one hour and two inch groups the next.

When the wind picks up I switch to soup cans and big spinners. Much more fun than paper! YMMV

 

[EPG]

Just got through embarrassing myself again at 100 yards shooting groups. Now I feel wind plays a serious factor, especially swirling winds that change direction often. Even at low levels, about 4-6 mph. Now I was consistently shooting 3/4” 5 shot groups at 50 yards. Best being 1/2” group. But at 100 yards? 3” to 3.25” . This has usually been 3 within an inch 1 about 3/4” away from them and the last more than 1.5 inches from any others. Would those wind conditions affect 40-42 grain slugs like that? Because if you do a straight extrapolation, my groups should only expand to 1-1.5” even with my limited skill. The 50 yard results appear to back that.

My experience is that pellets seem to hold amazing accuracy out to 80 yards with a rifle that very accurate at 50.

Beyond 80 yards, wind and/or pellet instability seems to become amplified.

Even 30 caliber pellets can get pushed around.

Look at these two 100 yard groups (these are darn good 100 groups for me). 4 of 5 touching in both groups, and the 5th shots get pushed way left by some “unexplained force”.

I have never shot slugs, but those who do seem to feel that they stay on their flight path better than pellets beyond 80 yards.

I’m going to start shooting and tuning for 75 yards - using .22 and .25 calibers - to see how good they can get. I’ll leave 100 yards to .30 caliber… losing interest in that distance for now.

 

[Troy Bakel]

Most common expression uttered at PSA by high power, smallbore, and pneumatic competitors shooting 100 yards.

Usually after being caught out by a shifting wind while looking through the scope.

Worst case is wind flags in your field of view have not changed but every flag you cannot see has spun 180°.

 

[Motorhead]

Case in point for the FT game ...
I came up with this idea a few years ago of having a telescopic mast ( Antenna ) that mounts on the scopes center line, having a drop string and custom flagging tip. * Feathers or odd shapes DON'T WORK as they flutter about, this type just sits still pretty much.
It extends out and above your line of sight threw your optics BUT CAN BE VIEWED with your non scope eye ( Shooting both eyes open )
Being it is over the scope out around muzzle out in open air it is very accurate in showing you air movement direction switches, and with some practice some relative speed changes by how far the flag is getting drawn back in the prevailing breeze.

Many of our clubs members have adopted similar wind flag systems on there FT guns