I'm posting this here in the Reference Material forum per another member's request. Hope this is helpful to all.

Example of how to calculate amount of movement (drift) for rear sight alignment:

Shots hitting 6-inches left at 100 yards: Measure distance between front and rear sights in inches. Divide result by 3,600 (number of inches in 100 yards). Multiply the result by 6 inches (number of inches shots hit off center). (i.e., Distance between front and rear sight = 20". 20 divided by 3,600 x 6 = .033 which is about 1/32"). Move/drift rear sight 1/32" to the right (direction you want shots to go in this example). You should be dead center or very close.

Example of front sight replacement:

If you are still hitting about 6-inches low at 100 yards and your rear sight is adjusted as high as it will go, replace the front sight with one that is at least 1/32" higher. A 1/16" higher sight would be best as it would allow plenty of room for both up and down adjustment.

Most people don"t realize and are surprised that it takes VERY LITTLE MOVEMENT of iron sights to adjust them for correct sight alignment.