How to Sight in AR 15 Iron

by Jeremiah Blanchard

The AR-15 is a shoulder fired, gas-operated, air-cooled semi-automatic assault rifle. This weapon is similar to the U.S. military service rifles known as the M-16A2 and M4. As with all weapons, accuracy depends on a proper sight picture. The AR-15 comes equipped with adjustable factory iron sights. The front and rear sight must be sighted in (zeroed) prior to using the weapon for target or hunting purposes. The sight-in procedure should be performed upon first receiving the weapon.

Set a target out at 25 meters. Get into a comfortable and stable shooting position.

Flip up the small rear sight aperture. This is the smaller circle on the rear sight pivot pin.

Turn the elevation knob until it reads 300 meters, inline with the corresponding hash mark number 3.

Look through the sight at the front post. Center the front sight post within the rear sight aperture. Position the top of the front sight post in the center, bisecting the rear sight aperture. When sight picture is correct, the top of the front sight post will form a horizontal line across the center of the rear sight aperture.

Aim at the bull's-eye. Fire a shot at the target and note the strike placement in relation to the bull's-eye.

Depress the detent pin on the rear sight post with a dummy round or cleaning rod. Rotate the sight in the direction that you need the impact to be. Clockwise rotation moves the post and the impact up. Rotate the sight by one click at a time, then fire another shot to check your adjustments. When your shot is landing on the bull's-eye, your rifle is sighted in (zeroed) for 300 to 800 meters.

Items you will need

  • Target
  • Cleaning rod or dummy round


  • Document your initial sighting adjustments. Refer back to these adjustments if the rifle needs to be sighted in again in the future.


  • Never attempt maintenance on a loaded firearm.
  • Never point an AR-15 at anything that you do not intend to shoot or kill.