Open sights are typically installed by a rifle manufacturer as a "default" sight of sorts, replaceable only by installing new sights or scopes. The open sight, sometimes referred to as an iron sight, is a basic sighting instrument in which the rear sight is a flat piece of metal with a "U" or "V" shaped groove cut into the center. The front sight is aligned--via the shooter's eye--in the rear groove center, with the top of the front sight post even with the top of the rear sight. Once the sight is aligned correctly the bullet should strike at the top of the front sight post (as seen through the eye) on the target. Adjusting an open sight is generally a universal process with most rifles.
Items you will need
Plastic tip screwdriver
Plastic hammer
Brass or plastic drift, or wooden dowel.
Locate the rear sight adjustment screw or step-slider mechanism to adjust the sight for elevation or windage. A step-slider can only be adjusted for elevation, while a screw adjustment sight can typically be adjusted for windage only. All rifles will differ slightly, but these two features are typical for open sights. The sight adjustment screw will be either in the rear sight's top center or on the side. The step slider is recognizable by a series of stepped notches under the sight.
Slide the sight forward to raise the elevation on the open sight if you have a stepped-slider adjustment. Pull the sight back to lower sight elevation.
Unscrew the sight adjustment screw--if you have open sights with adjustment screws. To avoid marring the weapon, use a plastic tip screwdriver to loosen the screw.
Drift the sight to the left or right to compensate for windage. Use a plastic or brass drift, or a wooden dowel. Hold the drift on the side of the sight, and use a plastic hammer to lightly tap the sight to the right or left to position your sight where you need it. Only move the sight 1/32 inch at a time in between test firings. Fire the weapon to ensure that the round is landing on target, or closer to the bull's-eye.