How to Measure Scope Height: An Easy Guide to Precision Shooting

How To Measure Scope Height

Accuracy is your best amigo when it comes to guns and rifles. So, cutting corners will only result in your shots being as scattered as a group of startled geese in a thunderstorm.

The question is, how do you get your shots right on target? The answer is you fix your scope height. Scope height is the distance between the centerline of the barrel of your rifle to the center of the scope tube.

So, to keep the trees from rolling their eyes, let’s learn how to measure scope heights and explore various ways to determine ideal sight height.

Why Is Scope Height Important?

Why Is Scope Height Important

The term ‘height over bore’ or sight height is a measurement typically requested by ballistic calculators to assist in calculating necessary adjustments for your rifle setup. Scope height is relevant for a few but important reasons: alignment, accuracy, repeatability, and fresh meal on the table.

Just like you would need some meat on a spit at the end of the shooting day, your rifle also needs scope dope for better results. You must be wondering why I am mentioning scope dope when all you had to learn about was scope height. Well, did I not mention ‘repeatability’?

Just so you know, scope height sets the stage, and scope dope is the script that tells you how to hit your target in various conditions.

One can get useful scope dope only if the bullets are behaving well, not by any chance but repeatedly, and the bullets will behave well if the scope is sitting at just the right height on the scope mount.

So, in a nutshell, they are working like a sheriff and a deputy. One cannot work without any help from the other one. Fix your sight height because only proper scope height will give you useful and accurate scope dope.

In a nutshell, they are working like a sheriff and a deputy. One cannot work without any help from the other one. Fix your sight height because only proper scope height will give you useful and accurate scope dope. So, the typical sequence would be to get a correct sight height than sight in a scope, in a result, you will get useful scope dope.

The Formula for Measuring the Scope Height

Here is the lowdown: scope height determines the gap between your line of sight or sight picture and the bullet trajectory. Your scope’s role is to make sure these two lines have a friendly chat.

Now, do you identify the exact purpose of the scope? Its function is not only to bring the distant targets up close but also to align your line of sight to the bullet’s flight path

If the scope is mounted too high on scope rings, your bullet’s flight path will not change much, but the connection between that path and your line gets disturbed. It is the same with iron sights; a wrongly mounted sight with an improper ring height will give you nothing.

In case you don’t know, a bullet’s trajectory is the path that the bullet takes from the moment it is fired until it reaches the target. The path is curved, and this curve is influenced by many factors like the bullet’s speed, the angle you are shooting (factor in scope height), and the forces like gravity and wind.

how to measure scope height

Simplest Method to Finding Scope Height

Simplest Method to Finding Scope Heigh

Without further ado, let’s get down to learning how to measure scope height. There are many methods to calculate sight height. Out of those, one of the simplest methods to get the measurement is to measure the distance from the center of scope rings or scope to the exact center of the barrel or bore.

Although it is a quick and speedy way, it is not a super accurate method.

Cleaning Rod Method

This method of measuring scope height is also quick and easy but also a bit more accurate than the one mentioned earlier.

What you need to do is just remove the bolt from the gun and insert a cleaning rod through the rifle’s muzzle to establish a centerline. Then, measure the distance from the center of the scope to the center of the cleaning rod.

This procedure might not produce accurate results, but it is considered more accurate than the first case as mentioned earlier.

The Formula for Measuring the Scope Height: 4 Quick Steps

The last and most accurate method is to determine or calculate the sight height using some formulas for accuracy at long-range distances. Not a fan of math? Let me simplify it for you.

  1. Begin by measuring the bolt diameter using a Vernier caliper or any digital caliper. Divide the obtained value with 2.
  2. Find the diameter of the scope tube as well and divide it by 2.
  3. The third step is to measure the distance from the top of the rifle bolt to the bottom of the scope.
  4. Lastly, add all three measurements that you obtained.
most rifles with leupold mark

Still scratching your head? Let me try again with an example. Let me use an example of a Winchester Model 70 rifle in .270 caliber, paired with a Vortex Viper PST Gen II Riflescope, 4-16x44mm:

  • Bolt diameter: 0.720 inches. Half of this is 0.360 inches.
  • Scope tube diameter (30mm): 1.200 inches. Half of this is 0.600 inches.
  • Distance from the top of the bolt to the bottom of the scope or scope rings: 0.85 inches.
  • The Sight Height is calculated as 0.360 inches + 0.600 inches + 0.85 inches, which equals 1.810 inches.

Most scope companies use 1.500” scope height on weapons. However, I like to experiment with various combinations of bases and scope ring height ranges. I maintain a gap of approx. 0.030 to 0.50 inches between the underside of the front bell of the scope and the bore/barrel.

Final Thoughts

Now you know finding sight height involves a couple of common procedures. You will come across both simple and complicated ones, but the idea is to pick the one that works best for your situation.

Just remember that the scope height can significantly affect the accuracy of your rifle’s setup.

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