Most Important wind

[Greg Langelius *]

Re: Most Important wind

Look at it this way. Once it's on the new heading, it would take another deflection to change that heading.

 

[goober]

Re: Most Important wind

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Bryan Litz</div><div class="ubbcode-body">Lindy,
Yes. Once the bullet has changed direction, it will continue on that path until acted on by an outside force (according to Newton, anyway )

I know what your thinking, that the bullet has some lateral velocity, and in the absence of wind, the lateral velocity should decay just like forward velocity. That's sort of a confusing way to thing about it though. Think instead of the bullet as having changed directions. The wind put it on a different course. When the wind stops, the bullet continues on that altered course.

-Bryan </div></div>So then if the projectile reacts to the wind at its starting point due to say A 10MPH full value wind it doesnt matter what the wind is beyond that initial contact providing that the more distant wind is below 10mph as its course is already set and of course its does not encounter a verticle wind off a ground formation .If this is so then only the first zone wind matters -unless the down range wind increase in velocity .

 

[TiroFijo]

Re: Most Important wind

A good rule of thumb for wind deflection down range is:

D(r2) = d(r1) + 2*d(r1)*(r2 -r1)/r1

where:

D(r2) = wind deflection at range 2
D(r1) = wind deflection at range 1
r2 = range 2 (longer)
r1 = range 1 (closer)

for example,

Sierra MK 175 gr HPBT @ 2700 fps, std. cond., 10 mph full value wind:

wind deflection at 300 yds (r1) = 6.6"

so the impact at 1000 yds of this 0-300 sector is:

wind deflection at 1000 yds = 6.6" + 2*6.6"*700/300 = 37.4"

 

[Greg Langelius *]

Re: Most Important wind

Ch'e...., maybe. The effects of the wind are not instantaneous. This is not a solid collision, like a ricochet.

Assuming a constant 10MPH wind all the way downrange, the effect is something like an acceleration over the entire time of flight. Imagine a second force of gravity working sideways, the effect is a curve, something sorta parabolic. The projectile's sideways velocity may never actually reach that of the wind, probably won't, in fact. Alterations in subsequent wind force and direction will distort the curve.

*<added>* All zones matter. There is no such thing as a force acting on the bullet without there being an equal and opposite reaction, Newton's Third Law demands it. The point here is that forces acting later in the trajectory create deviations that have a lesser portion of the trajectory to prevail upon the projectile's path. Therefore, to have a similar action or counteraction, they must provide more force acting over less time. It's a sliding scale that prejudices toward earlier forces having larger overall consequences. *<added>*

TiroFijo, thanks for the precision. Might you agree that nature's ways are so complex and constantly changing that computations, though precise, end up being only approximations in the end?

Greg

 

[9H_Cracka]

Re: Most Important wind

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: ch'e</div><div class="ubbcode-body"> .If this is so then only the first zone wind matters -unless the down range wind increase in velocity . </div></div>

Really - what if the downrange wind is 5 MPH the opposite direction of the 0-300 yd wind? No effect on the flight of the bullet huh?

Glad to learn that today.

 

[Greg Langelius *]

Re: Most Important wind

<bump> Please note the addition to my latest post.

 

[TiroFijo]

Re: Most Important wind

Greg, of course I agree... like Bryan said all this theoretical knowledge of how the wind moves the bullet is nice to play with in the computer "what if" games and have some idea of how to compensate for it, but nothing beats actually doing it in the range... which is kind of an art.

I understand there are currently some laser devices under development that can measure the wind downrange in several zones, and provide real time data to the ballistic computer, but they are not yet practical for field use.

 

[Greg Langelius *]

Re: Most Important wind

I keep getting the feeling something like that is active in some astronomical telescopes and tank gun aiming systems.

 

[CoryT]

Re: Most Important wind

What actually happens is the bullet turns its tip into the relative wind, rather like a weather vane.

Once aligned with the air mass, the vector has changed. That's why Bryan's chart shows the 300 and 700 yard wind like it does. Once the vector has been changed, traveling into still air changes nothing. There is no 'sideways velocity component', just the change in vector. If you added a chart that reversed the direction at 700, you'd see that would not get it back to zero.

Outside of a computer simulation, it's pretty hard to arrange these conditions, but that is what would happen.

I'm still waiting on the laser inferometer that gives crosswind velocity. In the meantime, a wind meter, spotting scope and experiance will have to do.

 

[JRose]

Re: Most Important wind

Gotta throw a tag in here.

 

[goober]

Re: Most Important wind

Do you guys use Kestrels or other devices to make intial wind calls or with long years of experience dont see the need for these devices ??

 

[Lindy]

Re: Most Important wind

The best use of a Kestrel is to use it to learn to judge the wind without the Kestrel.

In other words, estimate the wind you feel and hear, then use the Kestrel to measure it. Do that over time until you are have learned to judge the wind with fair accuracy.

That's necessary because you will often not have time to use the Kestrel when shooting.

You can use a laser range finder the same way to learn to judge distances by eye.

 

[goober]

Re: Most Important wind

Is theRE such a chart , illustration or book showning how wind flows over different terrains ? I have seen basic single page diagram in Plasters book but little more .I know there are a few wind books out in the States but definately nothing here in NZ

 

[BryanLitz]

Re: Most Important wind

I found this link very interesting. It's geared towards understanding wind patterns over terrain for the purpose of fire fighting:
http://training.nwcg.gov/pre-courses/S390/FireWeatherHandbook/pms_425_Fire_Wx_ch_06.pdf

-Bryan

 

[gugubica]

Re: Most Important wind

I think a distinction needs to be made here. If the question is at what point the wind effects the path of the bullet most, the answer really is both.

The argument that it affects it the most at the muzzle is a solid argument from an angular measurment standpoint only. It is true that any change in flight close to the muzzle is going to have the greatest effect in the final position.

But, wind does not effect the actual bullet as much at that point as it does at max ord.

So, basically, wind at the muzzle effects the trajectory more. Wind at the max ord effects the projectile more.

Did that make any sence at all (it made sence to me, but that does not mean it does to everyone else)?

Reading and adjusting for wind is very much an art. There really is no science to it. Yes, you can generate scientific readings of wind values, but they are essentially useless until you apply experience and feel to it.

A really good experienced shooter "feels" what they should do to compensate for wind. They just know how to counteract it, they don't overthink it, and really can't explain it to someone else very well.

 

[CoryT]

Re: Most Important wind

If you are looking simply from the standpoint of what wind would move the bullet the most horizontally for each yard travelled, that would be the wind at the target, where the bullet has the least forward speed and lowest BC.

If you are looking at what wind would make the most horizontal deflection in a narrow, say 100 yard band, at any specific distance, that would be at the muzzle.

In neither case is the effect greater at max ord.

From a practical standpoint, one must average out the total crosswind value over the entire range. Using a wind value from any one point will only work if that is the only wind blowing.

 

[TiroFijo]

Re: Most Important wind

These are the aproximate effects of a 175 SMK @ 2680 fps, standard conditions, with a 10 mph 90º crosswind:

Sector (yds) - Wind Drift in that sector (in) - % of total drift

0-1000 - 97,6" - 100%

100-1000 - 84,3" - 86%

200-1000 - 71,0" - 73%

300-1000 - 58,1" - 60%

400-1000 - 45,6" - 47%

500-1000 - 33,9" - 35%

600-1000 - 23,0" - 24%

700-1000 - 13,6" - 14%

800-1000 - 6,3" - 6.4%

900-1000 - 1.6" - 1.6%


And conversely:

Sector (yds) - Wind Drift in that sector (in) - % of total drift

0-100 - 13.3" - 13.7%

100- 200 - 13.3" - 13.6%

200-300 - 12.9" - 13.3%

300-400 - 12.5" - 12.8%

400-500 - 11.7" - 12.0%

500-600 - 10.9" - 11.1%

600-700 - 9.4" - 9.6%

700-800 - 7.3" - 7.5%

800-900 - 4.7" - 6.9%

900-1000 - 1.6" - 1.6%


This is valid of course for loads with similar BC and velocity.

This is assuming the crosswind is constant. If the wind has a velocity gradient with elevation above ground you would have to introduce a correction factor for the drift in the different sectors.

For example, maximun ordinate is close to 136" (3.78 feet) at 575 yds. If you estimate the wind in this sector at 13 mph because is higher above the ground then the % of total drift in this sector would be 11.1*1.3 = 14.4%

And then you have to introduce the correction factor for direction of the wind in each sector (cos angle), because most probably the angle is not 90º for the entire range

...

This is not practical for field use, unless you have a computer with real time imput from wind meters downrange, but is a mental exercise to "weight" the wind downrange.

Just to give you guys something to play with

 

[9H_Cracka]

Re: Most Important wind

TiroFijo, please re-post the table showing what velocity and BC your tool is using per 100 yard segment. I don't know where your figures came from, but the actual velocity and BC needs to be reflected in order to accurately depict what happens in a specific "band" of wind. Thanks.

 

[TiroFijo]

Re: Most Important wind

NineHotel, the varying velocity and BC in all brackets are already taken into account. I've used the Sierra values for G1 BC.

 

[9H_Cracka]

Re: Most Important wind

OK got it thanks. It does not take into account height above ground and varying velocity of the wind along the bullet's path based on height above ground though, so if one believes there is less wind near the ground than at the bullet's peak then the percentages are representative but not accurate.

 

[TiroFijo]

Re: Most Important wind

...just like I said, and also showed how to compensate for

This is a rather extreme range for this round (308 win), 1000 yds. The max ordinate for a 600 yds shot is only about 0.9 yds at 325 yds, and for a 800 yds shot is 2.0 yds at 450 yds.

The problem with the wind velocity gradient above the ground (which I believe is correct in most cases) is how to estimate it?? If it increases 1.0 mph for each yard above ground, the change is negligible for 600 yds shots, and is not very significant for 800 yds shots.

Edited to add: this is with a baseline value of a 10 mph wind. If the wind gradient is 1.0 mph increase per feet above the ground, but the baseline value is only a 5 mph, the effect is going to be greater. And of course the effect will be greater if the gradient is 2.0 mph per yard, etc.

 

[TiroFijo]

Re: Most Important wind

For the above example, these are the aproximate effects of a 175 SMK @ 2680 fps, standard conditions, horizontal fire, with a 10 mph 90º crosswind at bore level and increasing in speed at the rate of one mph per one yard of elevation above ground:

Sector (yds) - Wind Drift in that sector (in) - % of total drift

0-100 - 13.97" - 11.4%

100- 200 - 15.30" - 12.5%

200-300 - 15.60" - 12.7%

300-400 - 16.75" - 13.7%

400-500 - 15.91" - 13.0%

500-600 - 15.04" - 12.3%

600-700 - 12.88" - 10.5%

700-800 - 9.64" - 7.9%

800-900 - 5.78" - 4.7%

900-1000 - 1.74" - 1.4%

Note the total wind deflection is now 122.61", which would correspond to a 12.56 mph wind if it were constant.

 

[9H_Cracka]

Re: Most Important wind

There is a saying amongst us that actually shoot at distances from 800 to 1k yards. That is, the 100 yards between the 900 and 1000 yard line are the longest yards on the range.

Clearly your table would indicate otherwise.

I'll continue to make my wind shooting plan based on what I see happening to the projectile on the range, not what some computer program spits out.

 

[gugubica]

Re: Most Important wind

So, your program is telling you that a projectile traveling at over 2800 fps (when the BC is at its highest) is effected almost 14" for the first 100 yrds?

But, the same projectile going way slower and probably nose up in the air (where the BC is lowest) basically falling out of the sky at that point) is only effected by the same wind 1 3/4" in the same distance?

I gotta wonder about that. In fact, I have shot 100 yards in damn near tornado force winds and have never have to dail in 14" of windage.

eta: so is this from the right or the left, because it will give you different corrections at this distance.

 

[Noel Carlson]

Re: Most Important wind

Gugu,

He is saying that 14" of the terminal off-set is generated in the first 100 yards.

 

[Lindy]

Re: Most Important wind

My software indicates that on a 1000 yard shot with my cartridge, a full-value 10 mph wind in the only the first 100 yards of travel requires a correction of 0.5 mils, while a full-value 10 mph wind in only the last 100 yards of travel requires a 0.1 mil correction. That would indicate the importance of the last 100 yards of flight.

 

[TiroFijo]

Re: Most Important wind

Nine Hotel, that's perfectly OK by me...

just respectfully let me say that (like some many other things in shooting) <span style="font-style: italic">there is a difference in what we think we "see" and what actually happens with the wind</span>. Like I said before, wind reading is kind of an art due to the complexity of reading it.

Gugubica, Noel nailed it

 

[gugubica]

Re: Most Important wind

OK, that makes more sence. I thought he was saying that the projo would shift 14" in the first 100 yards of flight.

I feel that I should point out that we are again, dealing with angular measurments. A deflection in the first 100 yards (even if it is a smaller angle) will have the greatest effect at the target. I tried to point that out for the benifit of those that are not total egg heads (like I obviously am, even though I misunderstood Tiro's posted results at first).

Sorry for the chalenge, I just needed to be set strait!

eta: my original comment explains this better "wind at the muzzle has the most effect on trajectory, wind at the target has the most effect on the bullet."

 

[9H_Cracka]

Re: Most Important wind

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: TiroFijo</div><div class="ubbcode-body">

just respectfully let me say that (like some many other things in shooting) <span style="font-style: italic">there is a difference in what we think we "see" and what actually happens with the wind</span>.

</div></div>

This coming from someone that also says, "This is a rather extreme range for this round (308 win), 1000 yds."

I'll take a whole pound of salt with your advice.

 

[TiroFijo]

Re: Most Important wind

Ouch!! please stop, you really hurt my feelings

Let me add that ALL advanced software that is being used for ELR shooting gives results pretty much like mine, closer wind more important by far... The data I presented is pretty much in line with Bill McDonald's (Sierra Infinity), and he is currently developing AND testing ballistic computers for the military.

You can ask the people that use the cheytac's ABC (advanced ballistic computer), etc. with good results.

Or ask Bryan Lizt for his opinion, he is a ballistician and competitive shooter too.

Or disregard everything here, if you think you already know everything.

 

[Noel Carlson]

Re: Most Important wind

9H,

I lend a great deal of creedence to hands-on experience, and from what I have seen of your posts, you are practiced in common sense also.

Your reaction is confusing me. TiroFijo is predicting (ideally) a ~1.4" drift @ 100 yards, and an ~1.7" drift between 900-1,000 yards in a 10mph crosswind. This seems reasonable to me.

How much larger would you like the drift number to be for the final 100 yards of trajectory, and how were you able to empirically estimate it?

Best,
Noel

 

[9H_Cracka]

Re: Most Important wind

Noel - my experience is rather simple.

800 is like a "long" 600. At 600, you can basically look most of the time at what looks like one wind from which you make your call, assuming you can get agreement that the wind is doing basically the same thing over the length of the path of the bullet. Changes seem to occur, how can I say it, more well defined. Often at 600 you can get away with just watching one indicator for wind velocity and direction, still keeping an eye out on the edges for changes. One can shoot 800 basically the same but with some watching for a mix of conditions between themselves and the target, but having a "one condition" mindset will pretty well keep them in the middle of the target.

900 is where I start to see more of a combination of values between me and the target, independent of watching the edges for changes. This is where the throwing a bucket of water on concrete effect starts to be really seen. Also, when you mess up, the value on the target will be lower than the same mess-up at 800.

1000 is a whole new game. Unforgiving under moderate/readable conditions, PUNISHING under difficult conditions. Nothing at all like a single digit percent change from shooting 900 reflected above.

Plotting the peak of the arc seems to be an indicator of just how different the 100 yards is between say 700 and 700 and 900 and 1k, though I don't have something handy that will do that.

Granted you can shoot a better 800 score by shooting it more like 1000, but I encourage shooters that have 600 experience to go ahead and shoot 800 on back, just to wet their appetite for true long range. That is why I'm running two Palma matches this year, to get the 200-300-600 shooters on back further. 800 is very doable, 900 tricky, and 1k will most likely eat their lunch. If they show up for a 1k match, establishing a zero will be a much bigger problem and once on paper the learning curve for 1k is very steep, possibly leading to them having a discouraging experience. Doing OK at 800 and 900 is confidence inspiring, even if they do get eaten alive at 1k.

My experience says 1k is a different animal. The numbers above lead you to believe it is just a little harder. I think anyone that has spent a moderate amount of time shooting 600-1k as I have would agree, which means many arguing with me have not.

People can poke all they want at square range/wind flag/sighter shooters, but the experience gained over many rounds with good indicators as to what is going on plus the confirmation of what comes up on the target can teach someone a lot about shooting in wind.

 

[memilanuk]

Re: Most Important wind

Leo,

Entertaining reading as I finish packing to go spend three days getting abused @ Rattlesnake

The sling shooters up here have a saying... 800 & 900 are just fore-play - 1000 is where you get f$ck3d!

I will throw in that at least around here - shooting KD of course - part of what kicks up the difficulty level is the time of day each yardage is shot. 800 - first thing in the morning, weather *usually* somewhat mild, or at least readable. By late morning/ mid/day when folks start rolling through 900... things are starting to get interesting. By early afternoon when we shoot 1000... well, by then the wind generators have done been spooled up to 100%...

Sometime I'd like to shoot the yardages in reverse order just to see if it made a meaningful difference.

YMMV,

Monte

 

[TiroFijo]

Re: Most Important wind

9H, what I wanted to say with <span style="font-style: italic">"there is a difference in what we think we see and what actually happens"</span> is that winning matches is an art and I don't pretend to teach you how to do it, but paradoxically it may not be the ultimate road to technical understanding of how bullets fly... remember the best instructors and shooters of the time wrote the old manuals that state that humid air is more dense than dry one, "20º F equals 1.0 MOA", "horizontal range" for slant shots, no mention of spin drift because they cannot see it, etc., all notions that have been proved wrong with time.

 

[Greg Langelius *]

Re: Most Important wind

I think the simplest way to put it is, the more I shoot, the less I know; and the less certain I am about what I do know (Maybe? Even? Perhaps? Sigh!).

Greg

 

[BryanLitz]

Re: Most Important wind

9H,
I agree with your observations and descriptions of the wind effects at different ranges. I also don't think that your (our) observations go against the data that TJ presents; I think it's just a matter of not interpreting the data right.

The data indicates that the wind in the last 100-200 yards is the least important. On the other hand, we know that shooting at 1000 is way tougher than shooting at 800 and 900. The difference is that TJ's data is for a 1000 yard shot, and you're comparing that to shooting 800 and 900. <span style="text-decoration: underline">The difference in wind drift between shooting 900 yards and shooting 1000 yards is not the same as the wind deflection in the last 100 yards of a 1000 yard trajectory.</span>

As an example, if you have 57" of wind deflection at 800 (typical for Palma equipment in a 10 mph crosswind), it turns into 97" at 1000. That's 40" in the last 200 yards. What TJ's data is showing is that the 97" of damage done at 1000 is mostly caused by the wind at the shorter range as opposed to 'happening' in the last 200 yards.

I'm finding it difficult to explain my thoughts clearly, but I really don't believe that our common experience on the Palma course contradicts TJ's numbers, I think it's just a misinterpretation of those numbers.

Monte also has a good point about why 1000 is tougher (later in the day by the time you get there and the wind is up). It seems like everything is aligned to make 800 easy (proportionally larger rings, calmer conditions early in the day), then everything aligns against you at 1000. I've often thought that the first 2 stages of a Palma course were just an annoyance that you have to go thru before getting the the part that will decide the outcome. IMO, it would be much better if the scoring rings were smaller on all targets at all ranges.

Monte, good luck at Rattlesnake! By the way I like that foreplay line

-Bryan

 

[Greg Langelius *]

Re: Most Important wind

Actually I have an idea about that scoring rings issue.

I would like to see F Class and Palma go back to using the same target. I would suggest that an XX ring, half the size of the X ring, be overlaid onto the target, within the existing X ring.

I think this simple fix could address pretty much all of the issues regarding ties and the like.

Greg

 

[Sterling Shooter]

Re: Most Important wind

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Greg Langelius *</div><div class="ubbcode-body">Actually I have an idea about that scoring rings issue.

I would like to see F Class and Palma go back to using the same target. I would suggest that an XX ring, half the size of the X ring, be overlaid onto the target, within the existing X ring.

I think this simple fix could address pretty much all of the issues regarding ties and the like.

Greg</div></div>

Super idea!

 

[CoryT]

Re: Most Important wind

Tiro, excellent points. As the saying goes, "It's not what you know that gets you in trouble, it's what you know that just ain't so."

Bryan, that explanation pretty much nails it. It certainly seems to most observers that the problem is that last 200 yards, when the reality is the angular error is actually induced early at a range where the effect seems small. When 1 MPH causes 1 MOA of deflection at 1k, but is completly invisible in it's effect at 100, or even 600, the impression is left that the "problem" is the last bit of distance traveled.

The reason that 1K is a "different animal" is quite simply that a very small change in the velocity or angle translates to a large movement on the target. No one can read wind to 1 MPH over 1000 yards. If you are real good, you can get a call within 3-4 MPH of the actual value, then correct from there. In a match, one then tries to fire subsequent shots when things look the same as when you got a good result. The problem of course, is that that lousy 1 - 2 MPH still can't be reliably seen. A 1 MPH error at 600 is only ~3", and so it goes unnoticed. At 1K, it's ~10.6", which is a problem you can see. Since the conditions don't look any different, it sure SEEMS like it's that last few hundred yards that's the issue.

 

[Victor Co Heather]

Re: Most Important wind

Tagged.

 

[Greg Langelius *]

Re: Most Important wind

I've hawked this idea for several years, down to the point where I just sorta throw it into the conversation these days as a sorta by-the-way. It just seems to hit a solid wall of opposition from folks who do F Class a lot more seriously than I do. Not sure why, but I've essentially given up on F Class for several reasons, not the least of which is that the last place I could actually get to that ran it discontinued all matches that require pit service.

I try not to beat any drums these days. Celia and I have our hands a bit fuller with each other's health issues, and getting out to do long drives while leaving her at home just doesn't seem to be a worthwhile activity lately.

I can still manage our local Club's FV matches and get stoked for each and every one.

Greg

 

[Lowlight]

Re: Most Important wind

One note to this wind discussion, as most of it pertains to range shooting, or reading conditions across some what known terrain features that contain the atypical indicators.

Since this is Sniper's Hide, also consider these problems at night and during less than perfect conditions when these indicators cannot be seen to any degree of clarity or accuracy, because you're trying to shoot from darkness into a minimum of light, or even when the mirage is not present.

We routinely shoot at night, and not always under nightvision, so the things like the trees, grass, and mirage are no longer as valid for use. It again falls back to the shooter.

We played with max ord again this week, all signs point to its increased importance, to which I normally just guess at based off the wind at the shooter, adding a few MPH to my wind reading thanks to my experience of being able to actually walk up and read it on the tower.

It's the great equalizer for sure, and if the method works for you its never wrong, but I also caution those who advocate using conditions that require reading "air" downrange to understand its not always that easy to see, or know, so a baseline is necessary in my opinion then you can start developing your own personal art form to tackle the problem.

 

[Keith Johns]

Re: Most Important wind

Screw meters and equipment.

EXPERIENCE.

I judge the wind at muzzle(me), and I'll take note of the type of terrain I'm in. Arizona has a lot a desert valleys. I know from hunting here since I was 6 what the wind does in these valleys. Add a little comon sense built from experience, and you can guess what the wind is doing down range.

I'm never on a bench, never have range flags, and dont have all day to shoot. So I use what little experience I have to adjust and let it fly.

After shooting long enough, your gut feeling is a better indicator that any instrument out there other than a LRF.

But that would mean you need to get out and shoot and get off Snipers Hide

 

[Keith Johns]

Re: Most Important wind

Starting at me, the wind makes a backward S shape down this valley in the AM.

Sometimes it seems straight away, sometimes left, sometimes right.

How are you going to meter wind 500 yards out? Instinct


Get out and SHOOT!

 

[Sterling Shooter]

Re: Most Important wind

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Greg Langelius *</div><div class="ubbcode-body"> Not sure why, but I've essentially given up on F Class for several reasons, not the least of which is that the last place I could actually get to that ran it discontinued all matches that require pit service.


Greg</div></div>

Too bad, as having pit service allows the shooter to better analyze shot calls.

 

[goober]

Re: Most Important wind

I know this might be a bit of a long shot {excuse the pun} but does anybody have any mirage photos showing changing angles to illustrate what your looking for in mirage patterns - it would be greatly helpful to myself and I am sure others who have never used mirage to gauge wind .For that matter even if someone knows a site that they can point me to that has this visual info online .cheers

 

[9H_Cracka]

Re: Most Important wind

Mirage does not really show "angles" well. A static picture of mirage does not really tell you much. You need to study its movement to understand it.

That said, both the Army and Marine sniper books have static drawings of mirage in them. So does this book: http://rifleshootingbynancy.com/

 

[sp388]

Re: Most Important wind

jump and tag