The sight height of your rifle is needed to calculate your ballistics accurately. Fortunately, this measurement is very easy to do and doesn’t ever change for that rifle.
To calculate your rifle’s sight height, first find the center of your barrel and scope. Do this by finding the diameter of both and then dividing by two. Lastly, measure the gap between your barrel and scope. Insert the numbers into the formula below.
Your sight height is the height of your sights above the bore’s centerline. For a scope, this is the distance between the center of the scope and the center of the bore. The calculation is not difficult but requires a set of calipers and removing the stock from your rifle.
I will walk you through this process using my wife’s hunting rifle.
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Step 1: Finding the Center of the Bore
Find the center of your bore. Measure the diameter of your barrel beneath the objective bell of your scope and divide by two. It is important that this measurement be taken directly under the objective bell. Most barrels are tapered, meaning that the barrel’s diameter differs from spot to spot. Unfortunately, you usually need to remove the stock to get this measurement.
The example is as follows.
Barrel Diameter / 2 = Center of Bore
0.794″ / 2 = 0.397″
Step 2: Center of Scope
Find the center of your scope. Measure the diameter of the objective bell on your scope and divide it by two. The objective bell is the front section of the scope. This calculation represents where your crosshairs are positioned.
Objective Bell Diameter / 2 = Center of Scope
1.848″ / 2 = 0.924″
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Step 3: Measure the Space Between
Lastly, measure the gap between the top of your barrel and the bottom of your scope. Take this measurement in the exact spot you measured the barrel diameter to get the most accurate number.
For my Wife’s rifle, that distance is 0.366″.
Step 4: Add it All Up
Add it all up. Take the three numbers you ended up with and add them together to get your sight height.
Center of Bore + Center of Scope + the Space Between = Sight Height
0.397″ + 0.924″ + 0.366″ = 1.687″
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Sight Height Application
Enter this number into your ballistics calculators to get the most accurate data. Don’t worry if you are off by a little bit on this calculation. In fact, many people just eyeball this measurement with a steel ruler, and it works for them. You’ll want to get as close as possible for long-range distances to get the most accurate data.
I ran all of the numbers above to the nearest thousandth of an inch to get the most accurate measurement. However, this level of accuracy really isn’t needed. When ordering custom CDS dials from Leupold, they need the number to the nearest hundredth(0.00″) of an inch to get the most accurate data.
If you want to see how much being off a little bit will affect your bullet, check out this article I did on that subject.
Written by: Kurt Martonik
Kurt is a Gunsmith, Reloader, Hunter, and Outdoorsman. He grew up in Elk County, Pennsylvania, where he became obsessed with the world of firearms. Following high school, Kurt enlisted in the United States Air Force as a Boom Operator, where he eventually rose to the position of Instructor. After his military service, he attended the Colorado School of Trades(CST) in Lakewood, CO for gunsmithing. Following graduation, he accepted a job at C. Sharps Arms in Montana, where he worked as a full time stockmaker and gunsmith.