Mirage.

sako6br

sako6br

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When shooting in mirage conditions, what's the best way to know where the target really is? Not sure if it was just a bad day or if corn stalks make things worse but boy my target was sure dancing today. There was not much wind, maybe 1 or 2 mph. Target was jumping up more than left to right.
Any suggestions from the experts would be nice. Thanks
 
There isn't really all that much you can do
other than wait for a little wind to move the mirage
and aim center of mass.If you want you could fire
a sighter to see where you are hitting.
 
For F class, that is pretty much what I do - send a sighter based on your best guess of the conditions and see where it lands. Adj, send the second sighter and if all goes well, it will hit where you expect.

Now you just drive as the conditions ebbs and flows.

It is really hard to shoot LR without some cues on where the bullet is landing.

Any areas where there is exposed dirt so you can see where the bullet is landing?

Wireless video is another option if you can't have a spotter out there. Spotting scopes are of limited use when distances stretch out and mirage is high.

Jerry
 
Changing atmospheric density caused by varying temperature which bends the light rays coming off the target results in mirage. Probably one of the best ways to learn how to hold and shoot in it is to do just that - shoot in the condition ,make notes of what is seen and the resulting impact. Mirage can hurt you or it can help you. In windy conditions ,mirage is an excellent indicator of switches or changes in direction and strength. Holding into the mirage is the general rule.Adjusting the sights can be done relative to how constant the condition and/or confidence of the shooter.
This target ,20 shots at 100m, was shot in a 15-20 km/h switching wind with heavy mirage as the morning air warmed. The hold was between 4 o/c on the 9ring ,3rd line from centre, and 9-10 o/c on the 9ring.
Good luck with your trials
100ydpossible.jpg
 
To help reading and learning the effects of mirage, mirage boards can be made with a felt pen and large cards. Even thickness and evenly spaced parallel lines made on the boards. The boards can be made in various sizes relative to the distance to the target. Place the board next to the target horizontally and vertically. Horizontal lines will better indicate a "boil" - no wind but image shift. Vertical lines will better indicate wind as the image shifts.
Your notes can be added to your range book.
 
Mirage may be more accurately described as deflection of light or displacement of the target image. If there is a bit of a breeze and what would be decribed as a "running" mirage, image displacement is on the order opf 1/4 moa. Any other shift in point of impact is most likely to be from the effect upon the bullet of the same breeze which was affecting the mirage. This 1/4 moa figure may be considered to be the average amount of image displacement. In other words, the image is going to jump around a bit so that displacement is from zero to, maybe, 3/8 moa but 1/4 is a reasonable figure and seems to work out.
Using mirage to judge wind velocity is more an art than a science since the appearance of the mirage will vary with the ambient temerature, humidity, and terrain as much as it will due to wind velocity. In addition, we are often viewing mirage at a point where it may not be indicative of wind velocity over most of the range. At long range, we are looking at mirage effects which are well below the bullet's flight path.
At times, when wind is negligible, we will see diffraction which, while it comes from the same source, is not running. In this case, diffraction can be much greater and I have seen a full minute of angle. Because the mirage is not running, the diffraction is truly unnoticable until after the shot is fired (not the best time to discover an error!).
In a running mirage, displacement of the target is often upward as well as in the direction of the breeze. The stronger the breeze, the less upward displacement of the image.
At short range, I believe the mirage is of more value as a wind indicator than at long range but it can be a valuable tool in either case.
When I'm seeing things particularily well, shooting in wind and mirage has an almost Zen-like quality (be the wind!). When I'm not seeing things so well, shooting in the wind and mirage has more of a S&M-like quality and can be a painful experience! Regards, Bill
 
dryfire said:
Changing atmospheric density caused by varying temperature which bends the light rays coming off the target results in mirage. Probably one of the best ways to learn how to hold and shoot in it is to do just that - shoot in the condition ,make notes of what is seen and the resulting impact. Mirage can hurt you or it can help you. In windy conditions ,mirage is an excellent indicator of switches or changes in direction and strength. Holding into the mirage is the general rule.Adjusting the sights can be done relative to how constant the condition and/or confidence of the shooter.
This target ,20 shots at 100m, was shot in a 15-20 km/h switching wind with heavy mirage as the morning air warmed. The hold was between 4 o/c on the 9ring ,3rd line from centre, and 9-10 o/c on the 9ring.
Good luck with your trials
100ydpossible.jpg
Click to expand...

That is some awesome wind reading.

Just started practising with a rimfire and working on ammo to use. What ammo were you using? What rifle?

Leeper, great explanation. I try and make mirage my friend but it is a fickle friend. But I know the feeling when you can 'see' it dance, it sure feels good.

Jerry
 
That session was one of those "Holy Grail" moments. Shot with an early '60s vintage Rem 40X with a 36x Leupold and Lapua Pistol Trainer ammo. It is true what Bill Leeper said about the sensation being almost Zen-like. The target is courtesy of kombayotch - his target for his F-class smallbore matches.
 
I have always loved shooting in mirage. I trust it more than wind flags because you see it directly between you and the target. Wind flags are often hundreds of feet away and several feet up.

Pick a condition and stick with it, plain and simple. Avoid "boiling mirage", because refraction does create both an error as to where your target really is and also, it tends to cause bullets to do funky vertical things. The further you shoot, the more mirage reading helps your game. Did I mention I love mirage??

A good spotting scope is your best friend. Focus half way between you and the target and use it to find one condition. You will - with practice- learn to use it for judging holdoff and this is where shooting with a partner to lear mirage reading skills really helps. CyaN1de and Shockman are two very good mirage readers as well. We use mirage when team shooting and we have been very successful.
 
Thanks guys, I think we're off to a good start getting all of the factors and ideas out onto the table. Can we break this down a little more?
Like...
A boil: Does it lift the image up from it's normal position?
or does it move it up and down from it's normal position?
Wind: If the wind flickers the image to the right or left 2", does this mean there will be a 2" wind drift?

Let's say that you're trying to shoot a pop can(on it's side) @ 400 yds.
The first shot must hit or it will run down it's hole.;)
Where is the real pop can in relation to the friggin dancing one?
So far it's been by guess or by golly!
 
Yes a 'boil' will raise the image of the target. A 'running' mirage that displaces the image of a target a given # of minutes does not mean the bullet will be deflected that same amount. Shooting in the condition is a trial by fire - this is where note taking is of value. There typically is just too much going on to trust to memory. Use of mirage boards can help to see the actual amount of image displacement. Make the boards with half or 1 minute lines and spaces.
Practice shooting in the conditions. All the best.
 
As I said before, a running mirage will displace the target image by a relatively minor amount but is an indicator of wind conditions. Because the amount of diffraction and the angle of the run will vary depending upon atmospheric conditions, there is no difinitive answer. In a running mirage, the average displacement of the target image will amount to an inch or so at 300 meters. The wind, indicated by the mirage, will probably move your bullet a lot more than that.
I have shot on a range where, at an ambient temperature of 107 degrees F and a 20 mph wind, the mirage was running much as it would on my home range with a third as much wind but at 70 degrees.
In the field, with targets of varying shapes and on the ground, the problems are increased since it is hard to get a gopher to hold still while you set up a mirage board. Regards, Bill.
 
Thanks, I'm starting to understand. Was reading on some other forum where it was said that a running mirage coming toward you can move the target image down making you think you have a boil. Is this possible as well? Can you have a boil with a light breeze say...1 or 2 mph? My problem yesterday was more vertical than normal.
 
"In the field, with targets of varying shapes and on the ground, the problems are increased since it is hard to get a gopher to hold still while you set up a mirage board. "

But hopefully,we learn from our practice sessions for when we go into the field and apply what we've learned. Actually all the gophers I've shot unwittingly carry their own and have bullseye like birthmarks.
Cheers
 
While vertical can be a result of mirage, it usually isn't. At least not enough of it to be a valid excuse!
With even a very light breeze, the mirage will run. Set up an object of known size sometime and just sit and watch it though your scope. If you can feel the wind changes, you may be able to correlate wind and mirage appearance but keep in mind, your observations may be valid for that day only. Regards, Bill.
 
Rule of thumb in shortrange Benchrest.................. NEVER EVER shoot in a boil.

Does not matter whether you may think the wind is coming into your face or at your back. A boil is a boil and is UNPREDICTABLE as to where your shot will go. Hold off until you see it running L to R or R to L. Just remember that if you pull the trigger in the L to R condition do not pull in a R to L cause you are probably looking at a shot going up and left unless you hold into the condition.
 
A trick I heard of some time ago was to set up a scope on a tripod and have it set on the target early in the morning before any mirage occurs. It is then a simple matter to check the position of the target in the "fixed" scope prior to taking your shot. If you find you are shooting in a variable wind condition though this will be of only limited help.
 
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