Various sights and how to use them.
What you see when you are aiming at a target is called the “Sight Picture.” For accurate shooting this relationship of sights and target must be correct and above all consistent from shot to shot.
The open sight: The front sight is usually either a post or a post with a “bead”. The open rear sight is usually attached just in front of the breech. It has a “U” or “V” notch. Some airguns give you an assortment of rear notches. There are three correct sight pictures.
Some air rifles are equipped with an aperture sight (also known as receiver, peep, or diopter sight). It may be purchased as an option for some air rifles. This is a very easy sight to use and it is far more accurate and faster than a open sight because there is less guess work in its use and the distance between front and rear sight (“sight span”) is much greater. To use an aperture sight, just look through the aperture or “peep”, find the front sight, and put the front sight on the target. When looking through the receiver sight try to ignore the aperture, do not try to “center” the front sight. The human eye cannot focus on three objects so far apart. The eye will automatically seek the strongest source of light coming through the aperture and this automatically centers the front sight. If you should install an aperture sight on an air rifle that has an open sight already on it, remove the rear sight after lining up the receiver sight with it (Aperture sights are not suitable for air pistols ).
NOTE: Most air rifles will require a barrel angle correction before installing an aperture sight.
This is the simplest and fastest to use of all since it has magnification and only one plane of focus. Also many scopes actually gather light or allow shooting when it would be too dark for iron sights. Put the crosshairs on your target and shoot. Adjust as per scope instructions. NOTE: Be sure that the scope that you put on your airgun is designed specifically for airgun use.
Most scope for firearms are parallax adjusted to 50 meters, where as airgun scopes are parallax adjusted to 10 meters. The scope must be factory adjusted for correct airgun range or have a properly set adjustable “Range Focus” dial at the front end of the scope tube or you will shoot inaccurately, as much as half-inch off at 25 yards (12mm at 23m).