M1A rifles are semiautomatic rifles modeled after the military's M-14 rifle. The rifle is chambered to use 7.62 mm (.308 caliber) ammunition and is fed by a detachable box magazine. The sights of M1A rifles are not zeroed by the factory, so it's up to you to sight in your rifle. The rear sight of the rifle is two large knobs, one on each side; the knob on the right controls windage (the horizontal axis) and the knob on the left elevation (the vertical axis). Each click of an adjustment knob will move your point of aim by one inch on a target set at 100 yards. When initially zeroing in your rifle, the front sight can be adjusted to move your point of aim laterally.
Set up your target in a range of approximately 100 yards. Adjust your windage knob so that the windage index line, located on the peep sight, is aligned with the center line of the windage gauge located below the peep sight on the receiver.
Turn your elevation knob counterclockwise until you bottom the adjustment out. Turn the elevation knob clockwise eight to 12 clicks. These settings are referred to as the mechanical zero.
Take careful aim at your target, fire three to five well-controlled shots and observe the location of the shot group. Adjust the elevation as necessary by turning the elevation knob clockwise to bring the shop group up or counterclockwise for down. The shot group should be laterally centered. If it is not, adjust the front sight by loosening the front sight set screw, located on the back of the front sight assembly, and turning the ring that is around the barrel in the opposite direction of your correction. For example, if you want to move your shot group left, turn the ring right (clockwise). Most likely only small corrections will be necessary turning the dial .008 inch will move your point the shot group one inch at 100 yards.
- If you made an adjustment to the front sight, remember to re-tighten the front sight set screw.