tip on how to measure scope ring height

How To Measure Scope Ring Height: A Step-by-Step Guide

There are steps that you need to take before you can maximize your rifle’s accuracy when shooting.

Knowing how to measure scope ring height is just one of many.

People spend a lot of time, energy, and money getting the right rifle scope, and rightly so.

However, most of them overlook ring height, which is just as important.

Even the best optics would be useless if you could not set it up properly on your rifle.

For this, you need to get the right scope ring.

Below are what you need to know so you can buy the right ring for your scope and rifle.

The Basics of Scope Mounting

After buying a scope for your rifle, the next step is to mount it properly.

This is the time to start looking at scope rings and, if necessary, a base.

These two terms mean different things, but they are both directly involved in mounting your scope to your rifle.

What Is a Scope Ring?

A ring is an attachment that wraps around the tube and attaches the scope to the rifle.

Some rings can be attached directly to the firearm, while others need a special mount or a base.

What Is a Base?

Not all rifles have provisions for mounting scope rings.

For these types of firearms, you need a separate attachment, and this is the base.

The base provides a means for the rings to get mounted to the rifle.

What Is the Scope Ring Height?

Simply put, scope ring height determines how far the scope will be from the barrel.

Manufacturers usually make scope rings in three heights: low, medium, and high.

A few brands additionally offer extra low or extra high.

Most shooters prefer the lowest ring height possible, where the clearance between the scope and the barrel is minimal.

In this setting, the scope’s line of sight is closer to the bullet’s trajectory.

It reduces the need for adjustments, be it holdovers or holdunders, as the distance from the target changes.

Important Considerations When Measuring the Scope Ring Height

There are two common scope ring height issues.

The scope will either be mounted too high or too low.

Each scenario has its own set of challenges, but you must understand one term: cheek weld before we get to them.

What Is Cheek Weld?

When aiming your rifle, it should touch your body in four places:

  • Left hand
  • Right hand
  • Shoulder pocket
  • Cheek

One hand steadies the forward part of the rifle while the other hand pulls the trigger.

The butt of your rifle rests on your shoulder pocket to counteract the recoil.  

Cheek weld refers to the contact between your face and your rifle’s stock as you sight your target.

A good cheek weld is where your dominant eye can look comfortably into your scope.

The only way you can achieve this is by mounting your scope at the optimum height.

how to measure scope ring height

Issues When the Scope Ring Height Is Too High

A lot of things can go wrong if you mount your scope too high.

First, you would have to take an awkward position just to get a clear view of your scope.

When this happens, you will notice that the cheek weld is insufficient.

It is harder to focus on your target, reducing your accuracy when shooting.

In worse cases, your improper posture will force you to change the position of your rifle’s butt on your shoulder.

This will lead to a stronger recoil, leaving you vulnerable to a host of potential injuries.

It is also possible for the recoil to hit your chin if your cheek is too far from your stock.

As for the scope itself, a scope ring that is too high provides more leverage for the recoil.

Over time, it will affect the accuracy and even cause damages to your scope.

Issues When the Scope Ring Height Is Too Low

This issue is more common as most shooters prefer to set their scope at the lowest possible height.

It happens when there is no more clearance, and the objective bell is already kissing the top of the barrel.

As you tighten the ring, the scope’s front gets pushed against the rifle, crimping the tube.

If the dent is big enough, it could damage some mechanical or optical components inside.

It would also be impossible to align the scope with your rifle’s barrel, which would significantly affect your accuracy.

How To Measure Scope Ring Height

There is a way to estimate the appropriate ring height even if you haven’t bought the scope yet.

It involves looking at the scope part with the biggest diameter, the objective bell.

Compute for the Scope Height

A combination of numbers identifies most scopes that you see online or in shops.

Here’s an example:

[Scope brand] 3-9×40 [Scope description]

The first number (three) is the lowest magnification, while the second (nine) is the highest.

The third number is the diameter of the objective lens, and this is usually measured in millimeters.

To know what scope ring you should get, begin by adding two to four millimeters to the objective lens diameter. 

This will account for the thickness of the scope’s body, and the sum will be a close estimation of its overall diameter.

Next, divide the overall diameter by two to get the approximate distance between the scope’s central axis and its outer edge.

Using the above example:

Minimum ring height = (40 mm + 4 mm) ÷ 2

Computing this gives us a minimum ring height of 22 millimeters.

Any lower than this and your scope will hit your rifle’s barrel after mounting it and tightening the fasteners. 

Measure the Scope Height

Things will be a lot simpler if you already bought the scope.

All you have to do is measure the diameter of your scope at its widest part, then divide it by two.

The best way to measure the diameter of your scope is by using a caliper.

If you do not own a caliper yet, it might be a good idea to invest in one.

You will find this tool very useful, especially if you plan on working on your own rifle.

How To Choose the Right Scope Ring

Your scope height is the minimum height of your scope ring.

It means that the distance between the ring centerline and the base should be a bit higher than this value.

If there is a separate attachment for the base, you should use it as the reference instead of the ring itself.

This will ensure that your scope has some clearance from the barrel, whether you use a separate base attachment or not.

Identify the Ring Height

If you look at the scope rings sold in the market, you might experience some confusion about the measurements.

Different manufacturers have different ways of measuring the ring height of their products.

That is why it is important to know about scope height first.

It can give you a more standardized point of reference and help you avoid confusion moving forward.

Manufacturers usually have two different sets of reference points when measuring scope ring height:

  • The center of the ring and the bottom side of the base
  • The lowest part of the ring’s inner side (closest to the base) and the bottom side of the base

First Method

If the manufacturer uses the first method, then you should not have any problems.

Just look for the lowest ring height possible that does not go lower than your scope height.

The difference between the two measurements should give you the clearance between the scope and the barrel.

Again, using the previous example for illustration, your ring height should be higher than 22 millimeters.

If you want a clearance of three millimeters, the distance between the ring centerline and the base should be 25 millimeters.

Second Method

If the scope ring manufacturer uses the second method, you would have to make a minor adjustment in your computation.

Still, it is pretty straightforward and should not cause any problems.

The first thing you need to do is find out what the ring diameter is.

It is the diameter of the scope tube, which is the part that the ring hugs to mount the scope.

Once you have the ring diameter, divide it by two to get the centerline.

If the ring’s diameter is 30 millimeters, its centerline is at 15 millimeters.

Just add this to the manufacturer’s ring height to get the distance between the centerline and the base.

To continue with our previous illustration, the manufacturer’s ring height should be 10 millimeters.

This will put the distance between the centerline and the base at 25 millimeters, giving you a clearance of three millimeters.

A Better Understanding of the Scope Ring Height

Getting the right scope is important, but so is knowing how to measure scope ring height.

It will allow you to find the right mounting accessory to match your scope and your rifle.

With a scope, a rifle, and rings that complement one another, you can maximize target acquisition and accuracy to its fullest.

NRA image banner

Popular Articles

Our Pick
Big Dawg Targets 250 Target Roll - 3" Inch Adhesive Splatter Targe
$19.95

splatter targets are a great way to improve your shooting day. They offer immediate feedback and you can easily see your hits all the way out to 300 yards.

Buy Now
Prices correct at the time of publishing
10/26/2021 08:15 am GMT
where are nikon scopes made

Where Are Nikon Scopes Made?

Nikon is an established brand that manufactures a wide range of high-quality imaging and optical equipment. The company has also made strides in the scope

Read More »

Leave a Reply

Your email address will not be published. Required fields are marked *

Like What You Just Read?

Want to get new articles in your inbox?
Sign up to our mailing list and we will email you as soon as new content is posted.
Don’t worry we won’t share your email address with anyone…

Like What You Just Read?

Want to get new articles in your inbox?
Sign up to our mailing list and we will email you as soon as new content is posted.
Don’t worry we won’t share your email address with anyone…