Mirage has more than one source. One is heat rising from the barrel especially when there is minimal wind, and becomes worse as the ambient air temperature goes down. Mirage over the length of the range or right at the target on the other hand is reduced by cooler temperatures.
Barrel heat mirage is easily solved by using a mirage shield attached to the barrel. Course and target mirage is harder to control, but in Canada due to cooler temperatures it can be less of a problem. For that reason some choose to use a zoom for long range shooting, at max powder during good conditions and back off some for poor conditions. However, the mirage is still there and needs to be compensated for.
Barrel heat mirage is easily solved by using a mirage shield attached to the barrel. Course and target mirage is harder to control, but in Canada due to cooler temperatures it can be less of a problem. For that reason some choose to use a zoom for long range shooting, at max powder during good conditions and back off some for poor conditions. However, the mirage is still there and needs to be compensated for.
That is beyond world championship shooting right there.
