It is crucial that you choose the mounting rings with the proper height to mount your scope. The main reason for it is, that if the scope ring doesn’t have the right height, it won’t be able to hold the scope properly. So, when you take out your rifle for shooting, the scope will easily fall off the rings due to the recoils.
Another reason is, that if the scope height is too low or too high, it can damage your scope. If the height is too low, it will create pressure on the scope body and will cause irreparable internal damage. If the scope rings are too high, the scope will wobble around them and will fall off the rings.
Therefore, whenever you want to buy a new set of rings, make sure you know the proper height of the scope rings you will need for your scope. In this article, we are going to discuss the most common ways to measure the scope ring height before purchasing it.
How To Measure The Scope Height?
Many shooters may not know that by knowing the scope height, you can easily understand what scope height they will need for their scope. The scope height tells you the minimum distance your scope’s center line needs to sit above the bore.
So, once you know the scope height, your job is to find out the shortest combination of scope ring and scope mount which will be taller than your scope height. For instance, if your scope height is 24mm, you need a ring and base combination that is around 25mm tall.
To help you find your scope height, below we have included a few steps that will make the process easy for you.
Bolt Action Rifle: If you own a bolt action rifle and already have a scope mounted on it, the following steps will make it much easier for you to find out the scope ring height for your scope.
- Back out the rifle’s bolt to the point when it’s roughly aligned with the end part of the ocular lens of the scope.
- Measure the rear of the bolt with a digital caliper. Then divide the number by 2. For example, your bolt’s rear part is .69” and if you divide it by 2, the number will be 0.345”.
- Now, measure the width of the ocular lens and divide it by 2. For instance, you’ve got a width of 1.74” and if you divide it by 2, the result will be 0.87”.
- Then measure the distance between the top of the bolt and the bottom of the optic. Let’s assume, you’ve got 0.91” of distance between them.
- So, what you need to do is calculate all these results together as in (0.345”+ 0.87”+0.91”). The total will be 2.185”, and this is the height of your scope. Now find a pair of scope rings that are a bit taller than it.
Gas rifle: The gas rifles don’t have much of a difference in the scope height measurement process. So, here we are going to repeat the same steps:
- Pull out the bolt and align it with the ocular lens.
- Measure the back of the bolt carrier group. Let’s say, it is 0.91”. Now, divide it by 2. The result will be 0.455”.
- Then measure the ocular bell. For example, it is 1.72”. Divide this number by 2. The result will be 0.86”.
- Next, you have to measure the gap between the top of the bolt carrier group and the bottom of the optic. For instance, the distance is 1.49”.
- Lastly, add all these results as in ( 0.455”+0.86”+1.49”). The total will be 2.805” and it is your scope height. So, now you have to find scope rings that are a bit taller than this.
What Are The Steps To Measure Scope Ring Height?
There are mainly two methods that different manufacturers use to measure the scope ring height such as:
- Measuring from base to ring center.
- Measuring from base to ring’s bottom edge.
Measuring From Base To Ring Center:
- Take the scope’s objective lens diameter. Let’s say, the objective lens diameter of your scope is 40mm.
- Add 2-4mm to the diameter. It is because the scope body has a bit of thickness to it. So, if you add 3 mm to 40mm, the total would be 43mm.
- Now divide the total by 2 as in (43/2). The center height will be 21.5mm. And that’s it! You’ve got your scope ring height.
Measuring From Base To Ring’s Bottom Edge:
- Divide the scope tube diameter by 2. If you have a 1” tube (25.4mm), its half will be 12.7mm. But if you have a 30mm scope tube, the result will be 15mm.
- Then add the base and the manufacturer’s ring height with 12.7mm or 30mm (depending on your scope tube diameter). And done!
Frequently Asked Questions
How high should your scope rings be?
The height of the scope rings depends on your scope height. So, it comes down to you to measure the scope height and also find out the height of the scope rings you need for your scope. For this process, we recommend you go through the steps we have included in the article.
What does 20 MOA mean on a scope mount?
MOA means Minute of Angle which is a standard measurement unit for optics. With this unit of measurement, shooters adjust their windage and elevation turrets. Hence, if your scope mount base happens to have 20 MOA, it means your scope is downward in elevation by 20 Minutes of Angle.
Will a 30mm scope fit in 1” scope rings?
No, you can’t mount a 30mm scope in 1” scope rings. However, if you want you can mount a 1” scope in 30mm scope rings. For that, you will need a spacer that will decrease the inner diameter of the rings.
Are the scope rings supposed to touch the scope?
There always should be a slight gap between the scope and the rings. Because if you over-tighten the rings, they will damage the scope. Therefore, keep the same amount of gaps on each side of the rings.
Conclusion
To sum up, before purchasing scope rings for your scopes. It is better to be sure of the right scope ring height you need. It will save you from a lot of hassles of refunding or returning the products.
Therefore, we suggest you follow the simple steps we have discussed here. Plus, don’t forget that the scope mountability varies according to the rail types. So, if you have a Picatinny or Weaver rail, you will need rings compatible to mount on it.
Similarly, if you have a dovetail rail, find the rings compatible to install on it. Hopefully, after knowing the ring height measurement process, you can make the best scope ring purchase. Good luck!