Tech Note

April 29, 1996

TECHNICAL NOTE 15: INSTALLATION OF NATIONAL MATCH SIGHTS

GENERAL: M16A2 rear sights, and the similar sights used by ArmaLite, tend to be cocked counterclockwise (when viewed from the top.) This is due to a spring and ball on the left side which assures that the sights are always biased to the same position.

Some shooters dislike the look of the angle the rear sight assumes. To correct this, the ArmaLite National Match rear sight bears a ridge at the front surface opposite the ball and spring. This ridge is used to square the sight with the receiver. The ridge may require fitting.

FITTING THE REAR SIGHT BASE: If the rear sight base is too tight to fit into the receiver, or if the base is cocked too far clockwise, the ridge may be stoned or filed down until the sight is squared with the receiver. The raw steel should then be touched up with cold blue and protected with oil or solid film lubricant.

Some parts sellers have tried to correct the cocked sight by placing a second ball and spring on the right side of the sight. This largely restores the slack tolerances, and is generally ineffective.

MATCH FRONT SIGHT: The match front sight is a blade post, not a square post. Two sides taper towards the muzzle, and the top slopes down toward the muzzle. These features prevent the sides and top from becoming visible if the rear sight is substantially elevated or moved to the side. The front blade sight must be adjusted in complete rotations.

Copyright © 1998 ArmaLite, Inc.