Unfortunately, I can only visualize his hedgerow, and I can’t imagine hedges being much over 6-8ft tall. And I can guarantee the bullet is WAYYYY above that height for 75%+ of its flight.
Dave
Hedgerows, Wind, Eddy effect on bullet
- Thread starter Turpentine
- Start date
Dave
Dave, hedge is probably the wrong word to use on my part. It's more of a narrow strip of very thick woods that is 35 plus feet tall.
DON'T QUOTE ME, THIS IS PLAGERISED. It just takes a little research on the Internet and evaluation of your particular environment to consider yet another external ballistics factor. Then add "eye of newt and toe of frog, wool of bat, tongue of dog, adder's fork and blind-worm's sting, lizard's leg and owlet's wing, ..."
I suggest you may want to also look up the subjects of maximum ordinate and ground roughness.
For dense shelterbelts with little through-flow, winds are reduced greatly near the windbreak, but wind speed fully recovers downwind about 15 times the height of the trees. More open shelter belts, e.g., thick shrubbery and single tree rows, allow more through-flow so wind speed is reduced less near the trees, but wind speed fully recovers downwind about 30 times the height of the impediment. Wind speed in both cases also is reduced upwind for a distance equal to 3 to 4 times the height of the impediment.
I suggest you may want to also look up the subjects of maximum ordinate and ground roughness.
Wind Breaks/Shelterbelts
Buildings, forests, and windbreaks (shrubberies or trees) reduce near-surface wind speed, having the most impact when the wind blows perpendicular to them. Many shooting ranges have tree-lines and/or berms on both sides, constructed primarily as a safety precaution, that also impact the flow of air. Trees lining the right-side of the range are a blocking force and the wind comes tumbling back. Shooters on the far-left can read a steady wind where the shooters on right have flags switching constantly.For dense shelterbelts with little through-flow, winds are reduced greatly near the windbreak, but wind speed fully recovers downwind about 15 times the height of the trees. More open shelter belts, e.g., thick shrubbery and single tree rows, allow more through-flow so wind speed is reduced less near the trees, but wind speed fully recovers downwind about 30 times the height of the impediment. Wind speed in both cases also is reduced upwind for a distance equal to 3 to 4 times the height of the impediment.
Very helpful. Thanks
This is pretty much exactly what I'm seeing with my flight and points of impact. Very helpful. I had searched but had not found a lot. Poling the pro's certainly helps. That's why I post on this site.
I’ve experienced this in a state championship match. Those of us towards the tree line were getting rolling winds and bizarre impacts. Others in the middle of the range had consistent right to left winds. Squading is always a chance.
WyleWD
Silver $$ Contributor
+1 Definitely agree with this drawing generally speaking. If during a windy period, someone would put some smoke on a range and watch how it travels up, down, and around, you'd be very surprised. JME WD
I do appreciate all of you guys bearing with me on this! It helps
Wind behavior over rough ground and vegetation is pretty tough to get a handle on. I once went to a range armed with a cylinder full of helium and some balloons. It didn't work. A tethered balloon was just pushed down to the ground by the wind. This was at the Whitefish Mt. Range and the flight path was way above ground. I have not fired 1000yds at the Deep Creek range, but it looks to have its challenges as well. I am truly impressed by the guys who shoot consistently well on these ranges. WH
Fast14riot
Gold $$ Contributor
Spend some time at a stream and study the Eddy currents behind rocks and such obstacles. It'll give you a good visual of what happens to wind.
I enjoy flying sport kites, the rule of thumb has always been stable air flow returns downwind 10x the height of obstacle.
I enjoy flying sport kites, the rule of thumb has always been stable air flow returns downwind 10x the height of obstacle.
I do fish rivers and tide water a lot. I actually live on a river. Or 50 feet from it anyway for the last 22 years. That's part of what got me thinking about this. That plus the weird results I was getting on an easterly wind.
I actually suggested this to some regular shooters at a club about 6-7 years ago. They do a wednesday morning gathering. I told them to get enough smoke bombs for every 100 yards. Then enough people to each light one at same time from each line. Then everyone pay close attention to what the smoke does! It could be a great learning experience for everyone there.
Bottom Fodder
Silver $$ Contributor
I think most that shot at multiple ranges have experienced the home range advantage the regulars have by learning the personality of the range. And if this is your normal place to shoot it would probably be worth doing a smoke bomb test
Fast14riot
Gold $$ Contributor
Go fly a kite, literally, if you can get it in the air in those currents.
Or, just a good old fashioned TP job on the trees, will be great wind indicators for a few days, lol!
Or, just a good old fashioned TP job on the trees, will be great wind indicators for a few days, lol!
I’ve surveyed a few ranges with Wind Zeros and what you are seeing is correct. The wind speed close to tree line is much less and a lot more turbulent. Your wind holds go down but your vertical dispersion goes up till you get close to the trees. Elevation also has a significant effect. Wind speed can double quickly as you get closer to the top of the trees
Thank you sir. I recall on particular day testing a load with 140s that vertical dispersion was terrible. This load had always shot really good ES and Sd and good groups. With that same load the week before on a different wind I had a 3 shot 3" group at 1000. I have another load with 147 that tends to hold the line a bit better.
That's amazing. I'll bet he had some serious money tied up in that. Since I don't have long range to shoot any more I have to make 200 yds fun.
I've been thinking about your original question and actual results. Then it hit me - wind behaves like water so yes, there are currents and eddies. I just don't know how to detect and adjust for them, or if its even possible.
I forget the price for the rifle but it required a special compressor that if memory serves me right cost around $3500 pre Brandon. He bought the setup so he could shoot on John's Island anytime he wanted without upsetting the neighbors.
I think one slight difference between air and water is air compresses when it hits something, making it denser, so the effect gets somewhat magnified. But, just trust the target. I think over analyzing this, like trying to equate mph to drift, is not a good thing. Just do what the target says and I think thats a better approach, myself.
Last edited:
Upgrades & Donations
This Forum's expenses are primarily paid by member contributions. You can upgrade your Forum membership in seconds. Gold and Silver members get unlimited FREE classifieds for one year. Gold members can upload custom avatars.
Click Upgrade Membership Button ABOVE to get Gold or Silver Status.
You can also donate any amount, large or small, with the button below. Include your Forum Name in the PayPal Notes field.
To DONATE by CHECK, or make a recurring donation, CLICK HERE to learn how.
Click Upgrade Membership Button ABOVE to get Gold or Silver Status.
You can also donate any amount, large or small, with the button below. Include your Forum Name in the PayPal Notes field.
To DONATE by CHECK, or make a recurring donation, CLICK HERE to learn how.