Choosing the right scope ring height is crucial for proper firearm zeroing and safe shooting. An improperly mounted scope can lead to frustrating inconsistencies, potential damage to your equipment, and even safety hazards. This guide will walk you through the process of accurately determining the scope ring height you need.
Understanding Scope Ring Height
Scope ring height refers to the vertical distance between the scope's tube and the top of the receiver (or rail) on your firearm. This height is measured in inches or millimeters. Selecting the wrong height can result in:
- Insufficient clearance: The scope may hit the barrel or other parts of the firearm during recoil, damaging both the scope and the gun.
- Poor eye relief: This leads to discomfort and potentially injury during shooting.
- Difficulty with mounting: You might struggle to fit the rings onto the scope and firearm properly.
Methods for Determining Scope Ring Height
Several methods help determine the appropriate scope ring height. The most accurate methods require physical measurements, but estimations can be made based on experience and readily available information.
1. Direct Measurement: The Gold Standard
This method provides the most accurate ring height determination. You'll need:
- Your firearm: With the scope bases (or rail) already installed.
- Your scope: The scope you intend to mount.
- A ruler or calipers: For precise measurements.
- Place the scope on the bases: Position the scope as if it were mounted, ensuring it sits correctly on the bases or rail.
- Measure the distance: Carefully measure the distance between the top of the receiver/rail and the center of the scope's main tube. This is your minimum required height.
- Add clearance: Add an additional 1/8 to 1/4 inch (3-6 mm) of clearance to account for potential variations in scope tube diameter and potential for movement during recoil. More clearance might be necessary for high-recoil rifles.
- Select ring height: Choose ring height that corresponds to your measured minimum plus clearance.
2. Using a Scope Ring Height Chart or Calculator
Many websites and firearm accessory retailers provide scope ring height charts or calculators. These tools require you to input the scope's objective lens diameter and the firearm's receiver/rail height. While convenient, they offer estimations; always verify with direct measurement for critical applications.
3. The "Visual Inspection" Method (Least Accurate)
This method is less precise but can give you a rough idea. Visually inspect the scope and receiver/rail to estimate the necessary clearance. This method should only be used as a last resort and should be confirmed with a more accurate measurement.
Factors Influencing Scope Ring Height
Several factors influence the appropriate scope ring height beyond the simple measurement:
- Scope Tube Diameter: Larger diameter scopes require higher rings.
- Recoil: High-recoil firearms need extra clearance to prevent the scope from hitting the barrel.
- Objective Lens Diameter: Larger objective lenses require higher rings to clear the barrel.
- Mount Type: The type of mount (e.g., one-piece, two-piece, cantilever) significantly impacts the required height.
Conclusion
Determining the correct scope ring height is critical for a secure and accurate rifle setup. While estimation methods are available, direct measurement remains the most reliable approach. Always prioritize safety and accuracy when mounting your scope. If uncertain, consult with an experienced gunsmith or professional to ensure the correct installation. Remember, the time spent on careful measurement is time well spent.
