Hedgerows, Wind, Eddy effect on bullet

[Turpentine]

This may be a really stupid question. I'll do that now and then. Guys where I'm from we don't get a ton of wind like some of you do. And I'm certainly not as seasoned as many of you at shooting long distance. It's more of a hobby and I do some long range depredation hunting. Our terrain is basically forested except for clear cuts and farm fields and pancake flat. Our elevation is 34ft above sea level and most of the time you can swim in the humidity. Where I practice out to 1000 yards and beyond I am basically shooting down the side of a 900 yard long hedgerow on the left about 20 feet from the bullets flight path. To the right is 900 by 200 yards of field generally planted in crops. I have noticed if I have steady wind coming from the left and being blocked by the hedgerow, many times the mirage will look like it's moving from right to left in my flight path. Strips of flagging tape also will drift right to left somewhat. It's almost like the wind is rolling over the hedgerow. If I look out farther into the open field the mirage and flagging appear to move left to right with the wind. This can make the call tricky at times. Of course I'm getting spin drift to the right which would counter the effects a little. Is my thinking sound here? Can hedgerows like this actually create an eddy effect behind them that could push down and move a bullet back toward the hedgerow? I'd certainly like to hear what y'all have to say.
Thanks

 

[Turkeytider]

I`ll be curious to see what those with more expertise have to say about this as well. Our range has thickly wooded, tall trees down both sides.. Sometimes it seems like the wind is funneled right down the range, other times it seems to switch about from one end of the range to the other. I think at times there`s a definite impact on my .223 at 500 yards that I have trouble accounting for. Doesn`t take much to be off of a 3or 4" gong at 500 yards.

 

[ebb]

My friend and I used to shoot at a berm that was the division between two properties. It was fairly high and went for miles in each direction. When the wind blew directly at our faces there was no telling whether the bullet would impact higher or lower than POA. I never have quite figured out why or how that worked. So I am in the same boat as you.

 

[Turpentine]

It pushes my 168 grain 308 bullets around until I just scratch my head and laugh sometime. The 65-06 makes it easier but even then I'll wonder at times. I'd like to go to a class sometime but after breaking my back I'm not very mobile and cannot shoot prone at all. Plus Brandon has made sure there's no extra cash around for that kinda stuff.

 

[Dave M.]

This may be a really stupid question. I'll do that now and then. Guys where I'm from we don't get a ton of wind like some of you do. And I'm certainly not as seasoned as many of you at shooting long distance. It's more of a hobby and I do some long range depredation hunting. Our terrain is basically forested except for clear cuts and farm fields and pancake flat. Our elevation is 34ft above sea level and most of the time you can swim in the humidity. Where I practice out to 1000 yards and beyond I am basically shooting down the side of a 900 yard long hedgerow on the left about 20 feet from the bullets flight path. To the right is 900 by 200 yards of field generally planted in crops. I have noticed if I have steady wind coming from the left and being blocked by the hedgerow, many times the mirage will look like it's moving from right to left in my flight path. Strips of flagging tape also will drift right to left somewhat. It's almost like the wind is rolling over the hedgerow. If I look out farther into the open field the mirage and flagging appear to move left to right with the wind. This can make the call tricky at times. Of course I'm getting spin drift to the right which would counter the effects a little. Is my thinking sound here? Can hedgerows like this actually create an eddy effect behind them that could push down and move a bullet back toward the hedgerow? I'd certainly like to hear what y'all have to say.
Thanks

Chances are your bullet flight is way above your hedgerow. Tall trees can certainly create an eddy effect as you describe.

 

[Retired shooter]

My best response is Bryan Litz books
My son & I have done a little bit of ELR type shooting.
From all the books I have read, & videos watched, wind is a constant pain. Wind coming at you will slow bullet down, moving point of impact low. Wind from directly on your 6 will speed bullet up, moving point of impact up.
As Dave M says your bullet could be well above the tree row, how do you compensate for that.?
Mirage that is boiling straight up could be calm wind, could be coming straight at you, or going 180 degrees away from you. Mirage leaning slightly left or right will tell direction of wind and speed. Watching the vegetation at the target, trees, leaves, grasses all give an indication of wind.

Wind direction at the shooter, versus wind at the target ?

More out there much more experienced than me. I have met and and talk with a really good ELR shooter, gathering good knowledge. What he says is it is all experience, and good ballistics programs.

Bottom line I guess is books, podcasts, Kestrel Meters, and good ballistics program, & experimentation

Good luck!

 

[Schippergreg]

My 100yd range behind my house is wide open for 1/2-3/4 of a mile to the north but has a tree line about 50yds to the south. A south wind will have my flags showing wind from the north and south at the same time. It can definitely cause an eddy effect.

 

[Turpentine]

Chances are your bullet flight is way above your hedgerow. Tall trees can certainly create an eddy effect as you describe.

it is more of an older grown up canal bank where they piled the dirt alongside the canal when they dug it. It's,,wabout 20 yards in width with trees in the 30 to 35 foot tall and very thick nasty undergrowth so the flightpath isn't near the top

 

[Knotwild]

I have to ask: what have you observed in your bullet impacts when shooting under these conditions? That's probably going to answer your question. I say that tongue in cheek because I don't have much experience shooting long range. But I do regularly shoot 22lr out to 200yds and I keep a steel plate painted, so when conditions change, I can shoot it and see what the wind did with my bullet.

 

[Turpentine]

I have to ask: what have you observed in your bullet impacts when shooting under these conditions? That's probably going to answer your question. I say that tongue in cheek because I don't have much experience shooting long range. But I do regularly shoot 22lr out to 200yds and I keep a steel plate painted, so when conditions change, I can shoot it and see what the wind did with my bullet.

At times you'll get shots that print lower than they would normally be. Just the other day I had a constant 10 mph hour wind coming from the left so I held into it somewhat thinking this shots gonna have to move to the right with the wind plus spin drift but it actually moved and grouped even more to the left at 800. After looking at the mirage a bit more plus that first group, I held slightly right and sure enough they landed perfectly centered. Certainly not what you'd expect with wind from the left. Even with it being partially blocked by the hedgerow.

 

[steve210]

Any terrain feature is going to affect how the wind moves. Watching moving water gives a fairly good example of air movements. Air moving over trees or a berm will often give you a reversal.

 

[Turpentine]

Any terrain feature is going to affect how the wind moves. Watching moving water gives a fairly good example of air movements. Air moving over trees or a berm will often give you a reversal.

I live on a river and fish tidal water quite a bit so that analogy makes perfect sense. It was knowing how water acts that originally got me thinking about this. I wish I could shoot more into the open part of the field but crops prevent that.

 

[steve210]

The air has the same eddys and swirls as a river does, there is a reaction too topography changes and barriers of all kinds. Until you have watched a field of wind flags you can't imagine how many different ways wind can move in a short distance.

 

[MislMan]

Take a highway safety flare and tie/secure it to a pole or PVC tubing about 6 ft long. You take up your firing position without a firearm. Have a helper walk to the 100 yard target, light the flare and walk toward you holding the flare out to their side. You watch the flare smoke and see how much it moves around and switches direction. Use additional flares as required.

 

[Knotwild]

I believe as Steve and Mislman do. A lot can happen in 800 yds. And whatever is causing the change might not even be close to your shooting lane.

My 200 yd range is 75% down a canopy covered road. The last 50 yds is open across a clear cut in one direction but walled in by young pines in the other 3 quadrants. Last time I shot I could regularly hit a plastic spoon at 200yds dead calm. Then a 5-8 mph wind started blowing from the open quadrant into the pocket and I tried to shoot my steel plate to see what was going on - my first shot was off 18" and I could never guess where subsequent shots would go. I packed up and left.

 

[Turpentine]

I appreciate all of your responses. I was hoping what I was feeling and seeing what the actual bullet was doing made some sense. I shoot my 308 practicing a lot because compared to 147s in my 65-06 the 308 magnifies my errors and helps me learn.
knotwild I was on Johns Island with a guy that had one of those souped up compressed air 357 pellet rifles. He had actually killed deer with it. Not my cup of tea I assure you. But it was amazingly accurate. We were shooting shotshell hulls at 100 yards. You could follow the pellet for 75% or more of its flight through the scope. The wind coming off the marsh was gusting so you never got the same shot twice.

 

[akajun]

Anyone that's ever shot at Camp Perry knows about the "Low End" of Viale Range. IE numbers 1-20 or so depending on who you talk to. If the winds coming from the west you're basically shooting in a no wind condition all day, where it gets scary is targets 20-40 or so, some people think that the wind is dropping down at those points but not consistently or if coming from any other direction is greatly disturbed, rolling back onto itself. S yes its a real thing.

Also at a range we used to shoot at fort polk, the mid range points were highly built up, and surrounded by woods of different height. You could see dust blowing multiple directions when the wind kicked up, different wind flag conditions, If you got to 500yds, you could take your spotting scope and play with the focus to see the different mirage at different ranges

 

[Dave M.]

My 100yd range behind my house is wide open for 1/2-3/4 of a mile to the north but has a tree line about 50yds to the south. A south wind will have my flags showing wind from the north and south at the same time. It can definitely cause an eddy effect.

I’ve seen this effect consistently on our 600 yard range that is fairly tree lined on both sides for the first 400-450 yards

 

[dgeesaman]

Chances are your bullet flight is way above your hedgerow. Tall trees can certainly create an eddy effect as you describe.

Absolutely true but the wind up close changes POI more than the wind far downrange.

I think you have to look at the contour of the top of the hedgerow compared to the actual path of bullet flight.

Whatever the answer is, it sounds like pretty tricky conditions.

 

[Turpentine]

Possibly but I do not think so from my estimates vs the flight path. Then 308 at 1000 may be getting close. It'll avg. 35 feet tall. It's not something you want to walk through either unless you're a rabbit. There are fully mature pines, sweet gums, and Oak trees in parts of it that are 50-55ft tall. A logger cherry picked it many years ago and aside from the mature trees that were left its a 35ft wall of dog hair thick pines, sweetgums, and briars. I guess instead of a hedgerow it can be described as a narrow strip of woods.
It's definitely a lot more tricky than the wind from the right coming across the open field.