Shooting Into A Mirage
Most riflemen believe that shooting into a mirage is very difficult and it can be unless you understand that a mirage may distort our point of aim but is highly useful in reading the wind. Mirages are actually very useful in helping us read the direction and speed creates of the wind. On hot days the heat rising off the ground surface in front of a target or game animal creates mirage. Windage data can be gathered by the mirage can be read much the same way as a flag can at a shooting range.
If you look inside the mirage you can see the direction of the wind by following the wave patterns given off the mirage. How the waves bends tells you both the direction of the wind and how fast the wind is blowing. The wind direction, however, can only indicate if the wind is blowing right to left, or left to right. The waves cannot tell you if it is a full value, half value, or quarter value wind. The value of the wind ( the angle of the wind) is something you have to determine without the aid of the mirage.
Wind speed is determined by the wave lines contain within the visual image of the mirage. The more separation between the waves the slower the speed of the wind. The tighter the waves the faster the wind is blowing.
Mirages, however, can be deceiving. While mirages can help you determine wind speed and direction they can at the same time distort where the target location. Shooting straight at the target may result in a miss because the mirage is an optical illusion. To overcome this illusion try and follow the mirage’s movement across the target as you hold off center of the target. This is a tough skill to learn as a beginner but understand that a mirage can be your friend and your enemy. A mirage may make the target appear to be higher than it really is or it may make target seem like it actually further to one side. This distortion of target point of aim can be solved by lowering the magnification on the scope which provides a better sense of where the target is located. Or, another method is to distort the focus of your scope by turning back the focus ring to get a better image of the heat waves in and around the mirage.
On very hot days and low wind the mirage may appear to be boiling this makes the target appear higher up than it bends the target image off center.
The most common example of how a mirage impacts shooting is similar to the way a spoon appears bent when place in a glass of water, this illusion occurs because there is a light refraction coming from the water. The same occurs when viewed through your riflescope. The target sight picture tracks the variations of air temperatures between you and the target. This causes a change in the index refraction causing the image to appear blurred.
The direction of the heat waves coming off of the mirage may distort the true location of the target. The first task is to determine if the mirage is boiling or running and if so in what direction and at what speed. If the mirage is moving from right to left, it may distort the target to the left and you may have to hold right. If the mirage is running it may distort the image of the target to appear lower than then its actual position. Conversely, if the mirage is boiling the target image may distort the target image upward, requiring you to hold lower than the target appears.
In either case, shoot based on the properties of the mirage and then make an entry into your shooting log so you can learn what worked and what did not work. The more you practice predicting the effects of the mirage the more knowledge you will gain. By keeping a record log of your shots your learning will accelerate, soon you will be able to refer back to your notes when similar conditions arise.
President RTH Firearms