Choosing the correct scope ring height is essential for achieving optimal accuracy and comfort when mounting a scope on your rifle. The ideal height ensures proper alignment between your eye and the scope, maintains a comfortable shooting posture, and provides necessary clearance between the scope and the rifle.
Understanding Scope Ring Height
Scope ring height refers to the distance from the base where the ring attaches to the rifle to the bottom of the scope tube, where some manufacturers measure from the center of the tube. These heights are normally categorized as low, medium, high, extra-high, or ultra-high, though these classifications can vary between brands. Therefore, it’s important to refer to the specific measurements provided by the manufacturer, to choose the correct scope ring height.
Factors Influencing Ring Height Selection
- Objective Lens Diameter: Larger objective lenses require higher rings to prevent the scope from touching the barrel. For instance, a 50mm objective lens typically necessitates medium to high rings, depending on the rifle’s design, to ensure the appropriate scope ring height.
- Scope Tube Diameter: Common tube diameters include 1 inch (25.4mm) and 30mm. Ensure that the ring’s diameter matches your scope’s tube for a secure fit.
- Rifle Design: The rifle’s action type and stock design influence the appropriate ring height. Bolt-action rifles may require higher rings for bolt clearance, considering that it helps in aligning the scope and eye effectively.
- Mounting Base Height: The height of the mounting base or rail adds to the overall height. Measure this component to accurately calculate the required ring height for your scope ring height needs.
- Scope Placement: It’s also important to consider the barrel contour in relation to your scope’s position and design. For instance, if you’re using a scope with a large objective lens and need to mount it farther back to get proper eye relief—you may need higher rings to prevent the objective from contacting the barrel and achieve the correct scope ring height. Additionally, features like rear sights or other modifications may require extra clearance, making taller rings necessary to ensure the scope fits properly over the firearm.
- Rifle Action and Mounting System: Bolt-action rifles may need slightly higher rings to clear the bolt handle, while AR platforms often require extra-high rings or cantilever mounts to align with the shooter’s eye and allow clearance over the flat-top rail.
How to Calculate the Appropriate Ring Height
To determine the minimum ring height needed for your scope ring height:
- Measure the Objective Lens Radius: This measurement would be the complete outside of the objective, not just the lens size.
- Scope Tube Size: Determine your tube size, example A 30mm tube, 1″ (25.4mm) tube or 34mm
- Determine Base Height: Now measure the height of the mounting base or rail.
- Calculate Minimum Ring Height: Take your outside objective size subtract the tube size than subtract your base height. This will give you the minimum ring height in millimeters.
Below is the equation and an example of how to calculate the minimum ring height needed.
Minimum Ring Height = (Objective Lens – Tube Size)/2 – Base Height ÷ 25.4 = Minimum Height in inches.
So, let’s do an example of the Leupold VX5HD 3.5-15×44 scope being mounted on a Leupold BackCountry base. This scope has an objective size of 63.5mm and a tube size of 30mm, base is 9.5mm thick. We will determine which Leupold BackCountry rings would be needed. The correct scope ring height will be essential.
(63.5mm – 30mm) = 33.5mm ÷ 2 = 16.75mm – 9.5mm = 7.25mm or .285 inches. Note this measurement is the post height needed. Some manufacturers measure their rings from the bottom of the ring to the center of the tube, so with those rings you will need to add half of tube diameter size to the final calculation. With the example above Leupold measures from the center of the tube so we would need to add 15mm to the measurement give you a total needed of 22.25mm or .876 inches. The recommend size would be the Leupold BackCountry 30mm Medium’s.
As the objective lens (measured in millimeters) increases in size, the scope will require more clearance above the barrel. Ensuring correct scope ring height is crucial in matching the scope and rifle perfectly. As a rule of thumb:
| Objective Lens Size | Minimum Ring Height |
|---|---|
| 32mm or less | Low |
| 40mm – 44mm | Low to Medium |
| 50mm | Medium to High |
| 56mm+ | High or Extra High |
Tip: Add 2–4mm to your objective size to account for the scope covers when calculating needed clearance.
In Summary
Choosing the right scope ring is all about balance—between comfort, clearance, performance, and selecting the appropriate scope ring height. Take your time, measure carefully, and always prioritize a natural shooting position. The right setup makes all the difference, whether you’re chasing elk or punching holes in paper at 500 yards.