I just finished reading "Marine Sniper" by Charles Henderson. It is obvious that Mr. Hathcock was an excellent shooter. Following is from the book:

...he watched the mirage... - From that he could calculate the wind velocity by dividing the angle of the mirage by four. After determining that, he could multiply the velocity by eight, which represented this particular range in hundreds of yards, and then divide that again by four and have the number of "clicks" or half minutes of angle he would need for windage.

Is this for real ?

Just divide the first number by 2...same answer.

I don't know Henderson and have not read the book. Is it supposed to an autobiography?

It sounds as though it may have been embellished, a lot. I'm sure Hathcock used mirage as an aid in determining wind direction and velocity (all shooters do) but those complicated calculations sound like something out of CSI or Law & Order.

I've never heard of mirage flowing at an angle. I mean, the wind does blow at an angle but I've never heard of anyone being able to determine the angle from mirage. That's what flags do. And what did Hathcock do when there was no mirage?

There's no doubt that Carlos Hathcock was a real American hero and an excellant rifleman. But most riflemen of his talent are very much instinctive shooters who take in all of the environmental factors between themselves and the target and process it in a way that average shooters can't. I find it hard to believe that he would sit there dividing this by 4 then multiplying that by 8, then . . . JMHO

Ray

Gauti, Americans cannot shoot that well. At least not until they enter high school.

The angle of the mirage refers to the angle with the vertical. Mirage flowing straight up - no cross wind. As the wind picks up, the mirage bends over, until about 15 mph (somewhere around there) when it runs horizontally. At that point you have to start using other signals to check wind speed.

As for calculating a correction, maybe he did or maybe he just looked at things and said "This many should do it". He wasn't allowed sighters, so after his judgement call, maybe he did run the numbers to check.

l understand Hathcock used S.W.A.G. for
calculating the wind....

quote:

Originally posted by JohnD:
The angle of the mirage refers to the angle with the vertical. Mirage flowing straight up - no cross wind. As the wind picks up, the mirage bends over, until about 15 mph (somewhere around there) when it runs horizontally. At that point you have to start using other signals to check wind speed.

John D

That's a new one for me. Mirage with no wind is a "boil" and I've never noticed that it flows straight up. What would make it flow straight up if there's no wind? Or that it bends over as the wind picks up. So you're saying that with a 7.5 mph cross wind the mirage runs at a 45 degree angle? I don't think so. Mirage can be used to determine both wind direction and speed. But it's not the best wind reading aid because you are only seeing the wind at the distance where your scope is focused.

Ray

OK, a boil is what I thought about saying, but didn't feel ike explaining it, so I said straight up. As for the exact angles, I made no such claim, just that as the wind gets faster, the image of the mirage gets more horizontal, until it can't get any more horizontaler. At that point it's hard to read the speed because you (well, I) just see a side-to-side blur. Then its time to look at the grass, the trees, the wind flags or whatever else the range happens to have. At least that's what I do.

Tough to stay hidden with a computer, the extension chord would surely give you away.

Ray, I've never seen any mirage boards out in the field. Might put some up around the PD mounds next time I go out.
Butch

this is an exagerated example of sniper math for the layperson it kinda works like that but experience is what you use to judge wind by mirage. white feather had a lot of that

Ray, where is your next 1000 yd match? Sounds like things are going your way. I hope you have a good year.
Butch

Butch

I'm leaving next week for Sacramento to shoot the 600 Yard Nationals. I'll be using two 6PPC rifles, one with a 12 twist and 71 grain Bergers and one with an 8 twist and 95 grain BIB bullets. If the conditions get bad I'll have a 244 Ackley, just in case. The 1000 yard Nationals are in Reno, in July I think. That should be fun with those summer Reno winds.

Ray

quote:

I've never heard of mirage flowing at an angle. I mean, the wind does blow at an angle but I've never heard of anyone being able to determine the angle from mirage. That's what flags do. And what did Hathcock do when there was no mirage

In the excellent book, "The Ultimate Sniper" by John Plaster, reference is made to determining wind speed by the angle of mirage so there must be something to it.

I will have a great opportunity to watch it this weekend at a match in Tomball, Tex. Lots of mirage there. My experience is it runs at different speeds as the wind velocity changes. When you have a light wind the waves are slow and taller and as the wind speeds up it flows faster and the lines are straighter. I haven't seen the mirage lean at an angle.
Butch

Hello,
Perhaps saying at an angle for mirage is similar to statements often heard about the "mirage is running right to left like a river..." I have observed many times and it does take on the appearance of streaming from the earth surface similar to smoke blowing up and to the right or left or at least it does appear that way to me. Mirage going straight up or in a "boil" is not uncommon and not a good idea to shoot through a boil I have been told due to different reaction of bullet/flight.
If I have been observing mirage at say 1000 yards(almost always even in colder days) and then it goes away, rule of thumb taught to me was always hold up for the wind speed has probably exceeded 10mph. Double check other signs to make sure. Flags are somewhat of a nuisance for unless correct dimension, proper material, wet or dry, can give false reading of wind.
Military developed wind doping formulas years ago(Springfield 03 testing)for each clock direction of the wind. Concluded 6 and 12 have little influence on flight of bullet unless somewhat of a hurricane wind of course. Remaining clock face directions have separate formula. Somewhat cumbersome to remember and do all that math during a battle or anxious moments as they say. Down and dirty, quick to calculate method I and others have used for many a year is simply assume either full value wind,3/9, distance to target, speed of wind and divide answer by 1000. 600 yard range, wind est. to be 10mph, would simply be 6000/1000 or 6 minutes of windage, but that would be more than needed unless it is truly a full value wind. Divide the 6 in two or use 3 minutes and you will most likely be in the target face all other things being equal. The factor for a full value wind is 1000 and by dividing your answer in half is a compromise of the other possible direction factors. Speed of wind can be doped pretty close with experience and in a match, let some of the other good shooters shoot first and watch the impact/target results.
Unless their sling slipped, jerked the trigger, butt slipped off the shoulder, elbow slipped on the mat, you will see a pattern of shots from the more experienced shooters and wind problems will show up quickly.

Reading mirage has always been more of an art than a science but I'm sure the military would prefer to assign a number to it so they probably have. Iknow that on days when I'm doing particularly well, the mirage seems to make perfect sense and never lies.
As Cheechako said, the mirage is only visible were your scope is focused and the amount you see is dependeent on the depth of field of your scope. For this reason, I always felt I could read mirage better through a 24x scope than a 36 for instance. I also focus my scope a little short. If using a spotting scope, one can focus it at a distance which allows him to see the run at that distance. This is advantageous on those ranges which pass over varied terrain and which feature "tricky" wind currents. A range located on flat land with a prevailing wind is a different matter and the use of mirage is of less value. Mirage is also of less value at longer ranges. At 1000 yd., you are also looking at mirage well below the bullet's flight path.
There is also the displacement of the target image to be considered but this is normally not more than about 1/4 minute in a running mirage. Related to mirage but not the same is the defraction caused by layers of relatively still air of varying temperatures and density. I've seen cases where this type of condition was good for a full inch at 100 yd. Very difficult to manage. Regards, Bill.