Sights line the barrel up with the target, so they decide where the pellet or bullet goes. In ISSF rifle shooting you use a diopter rear sight and a front sight; on a pistol you use open sights.
Rifle diopter sight
A diopter is a rear sight with a small aperture that sits close to your eye. Your eye centers the front sight in the aperture on its own, so a diopter is more precise than an open notch at the same distance.
Many diopters take interchangeable apertures with different hole diameters. A narrow hole gives sharpness and depth of field but lets in less light. A wider one works better in dim light.
Many diopters also have light filters and adjustment for elevation and windage. Those mechanisms are what you use for zeroing and sight adjustments.
Front sight and inserts
The front sight sits at the muzzle end and usually holds a ring insert, with a clear gap inside. You hold the target in the center of that ring.
The ring size depends on the target and the lighting. A ring that is too small makes the target hard to see, and one that is too large lowers centering accuracy. There is no universal answer: it depends on your eye and the distance, so it helps to pick it with a coach.
Pistol open sights
A target pistol has open sights: a rear notch and a front blade. You align the top of the blade with the top edge of the notch and keep an even gap of light on both sides.
You can change the notch width and the blade size with interchangeable parts. The sight line also moves up, down, and sideways, so the weapon is set up for one shooter and one type of ammunition.
One focus
You focus on the front sight, not on the target. A blurry target with a sharp front sight is the normal picture.
Optical sights
Magnified optical sights are not allowed in every discipline. It depends on the rules of the competition and the discipline, so check the rulebook before the start. In ISSF rifle events, the main setup is a diopter and a front sight.
Caring for optics
- Wipe lenses with a soft, clean cloth, not with a finger or a sleeve.
- Do not take a diopter apart yourself. Misaligned mechanisms are hard to restore.
- Keep sights in a case so dust does not settle on the lenses.