Items you will need
The M1A rifle is a semi-automatic, cartridge-loaded rifle. It is the civilian issue version of the military’s M14 rifle. Springfield Armory, Inc. first designed and manufactured the M1A in 1974. The rear sights on the United States General Issue M1 Garand and M14 are identical to those of the M1A. The “peep” or “aperture” sight on an M1A supply a greater amount of accuracy and are easier to adjust for windage and elevation.
Sighting an M1A Rifle
Hold the rifle in firing position with the butt against your shoulder. Turn the windage knob on the right until the witness line aligns with the center of the scale. Turn the elevation knob on the left towards the barrel until it is as far as it will turn.
Zero the rifle. Clamp the rifle in the vise and bore sight a target at 100 yards.
Adjust the rear sights without moving the rifle. Use the windage knob to adjust horizontally and the elevation knob to adjust vertically. You now have a mechanical zero.
Go to a firing range. Fire three shots at a 100-yard target from a supported firing position.
If the rounds hit low, turn the elevation knob back until it becomes centered. If the rounds hit left or right of the target, adjust the windage knob until the shots become centered.
Continue firing three shots until you have verified that you have zeroed your rifle.
Each click of the windage and elevation knobs corresponds to one minute of a degree increment. Zero your rifle in a supported firing position, preferably prone with sandbags, as it is the most accurate firing position.
Always load a rifle with the safety on. Always point your rifle down range. Never look into the muzzle of a rifle unless it is disassembled. Also, use the proper 7.62 NATO ammunition in your M1A rifle.