There are 2 parts to compensating for bullet drift caused by wind.

1                 Strength of the wind

2                 Direction of the wind

1) The strength of the wind is gauged by looking at the wind flags. Look carefully at the angle of each flag and judge what the wind speed is. When shooting at longer ranges you may notice a different wind speed indicated by the wind flags closer to you than the ones further away.

Take more notice of the wind flags closer to you when averaging the wind speed as these are showing you the wind speed that will have most effect on the bullet.

Wind Direction is also important as this will affect how much the wind pushes the bullet off course.

A very strong wind blowing directly from the shooter to the target will for all intent have no effect. (the 6 and 12 o'clock position). The correction to compensate at 300 yards is 0 minutes of angle.

A very strong wind blowing at right angles to the bullets path will have the greatest effect (the 3 and 9 o'clock position). The correction to compensate at 300 yards is 3 minutes of angle.

It can therefore be seen that wind blowing from other directions will have an effect somewhere between the 2 extremes. In practice we use the numbers of the clock to indicate wind direction. For example the wind is very strong and blowing from 10 o'clock.

So let's see how this works in practice.

Our rifle has been zeroed and the Windage (left/right adjustment) scale reads zero minutes of angle.

Looking at the wind flags the estimated wind is judged to be ‘Fair’ and is blowing from 11 o’clock. Looking at the chart, find the sloping line that represents the 11 o’clock position and follow it down until it intercepts with the horizontal ‘Fresh’ wind line, then using the numbers at the bottom of the chart read off how many minutes of angle you need to set on the sights to compensate. In this example the amount is 1 minute of angle. The wind is blowing from the 11 o’clock position which is on the left hand side of the clock face so the sights are adjusted 1 minute left. Now when the bullet is fired the barrel will be angled in to the wind slightly which will compensate for the bullet drift.