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My Pattern 14 shoots about a foot high at 107 yards. The original front sight is marked 060 on one side ('14 on the other side). I have a set of replacement sights, but would like to know if anyone has a formula for calculating the height increase needed?
Thanks in advance for any assistance.
Bruce Sharer
Raleigh, NC
Front Sight Height Calculator
Frequently a change in the rear sight of a rifle means a taller or shorter front sight is desired. Determining the desired height is a simple calculation that is explained below.
1.Shoot a group (at least three shots) with the current front sight. This can be done from any known distance. Convert the range to inches. (i.e. 100 yards is 36X100 or 3600 inches)
2.Measure the distance the center of the group is from the desired point of impact in inches.
3.Measure the distance from the front sight to the rear sight in inches. This is called the sight radius.
4.The change in height needed is calculated by multiplying the desired change from step 2 by the sight radius in step 3 and dividing by the range (in inches) that the group was fired at from step 1.
For example:
Let's say our rifle shot 10 inches high at 100 yards and the sight radius of our rifle is 23 inches. We can calculate the amount of change we need in the front sight as follows:
Change = 10 inches X 23 inches = .064 inches or about 1/16 of an inch.
3600 inches
Now to order a front sight the correct height, You measure the height of the front sight on your rifle from the bottom of the dovetail to the top of the sight, add the change calculated above and ask for that height. Use a caliper or micrometer to measure with since you need to have an answer in thousands of an inch.
It is important to note that front sights adjust the opposite direction you want to move the point of impact. In the example above we were shooting high so we needed a taller front sight. If we were shooting low we would want a shorter front sight.
Rear sights adjust in the direction we want the move the point of impact. If we want to move the point of impact to the left we move the rear sight to the left.
That's excellent info RBruce...I should have known there was a formula.