How to Adjust a Crossbow Scope – A Comprehensive Guide

How to Adjust a Crossbow Scope

Adjusting a crossbow scope is a crucial step in achieving optimal accuracy and performance.

This article will guide you through the process of mounting, aligning, and fine-tuning your crossbow scope, ensuring that you are prepared to make precise and accurate shots in the field.

Understanding Scope Adjustments

  1. Windage: The horizontal adjustment on a scope, allowing you to correct for the wind's effect on the bullet's trajectory. Windage adjustments are typically made in increments of MOA (Minute of Angle) or MRAD (milliradian).
  2. Elevation: The vertical adjustment on a scope, allowing you to correct for bullet drop over distance. Like windage, elevation adjustments are usually made in MOA or MRAD increments.
  3. Parallax: Parallax occurs when the target image and the reticle are not on the same focal plane, causing the reticle to appear to shift when the shooter's eye moves. Some scopes have a parallax adjustment knob or side-focus knob that allows you to correct for parallax at different shooting distances.
  4. Magnification: Many scopes have adjustable magnification, allowing you to zoom in or out to suit the shooting situation. Adjusting magnification can affect field of view, brightness, and eye relief.

How to Adjust a Crossbow Scope

Adjusting a crossbow scope involves two primary tasks: mounting and sighting-in. Properly mounting the scope on your crossbow is essential for stability and accuracy, while sighting-in (zeroing) ensures that your scope is correctly aligned with the point of impact.

Here's a step-by-step guide to help you adjust your crossbow scope:

Mounting the scope:

  1. Before you begin, make sure your crossbow is unloaded and in a safe condition.
  2. Attach the scope rings to the scope according to the manufacturer's instructions. Ensure the rings are compatible with both your scope and crossbow rail.
  3. Attach the scope to the rail of your crossbow, ensuring it's properly seated and centered.
  4. Tighten the mounting bolts on the scope rings, but avoid over-tightening, which could damage the scope.
  5. Adjust the eye relief (the distance between your eye and the scope) by sliding the scope forward or backward in the rings. Proper eye relief helps you quickly acquire your target and minimizes the risk of injury from the scope hitting your face during recoil.

Sighting-in (zeroing) the scope:

  1. Start by shooting from a short distance, typically 20 yards. Use a shooting rest or sandbags to stabilize your crossbow, which will help improve accuracy and consistency during the sighting-in process.
  2. Aim at the center of your target using the reticle's center crosshair, and shoot a group of three bolts. Observe where the bolts hit the target in relation to where you aimed.
  3. Based on the group's point of impact, adjust the windage and elevation knobs on the scope. These adjustments usually have click increments, with each click representing a specific change in MOA (Minute of Angle) or MRAD (milliradian). Check your scope's manual for details on the click values and adjustment directions.
  4. Make the necessary adjustments to the windage and elevation knobs, then shoot another group of three bolts. Repeat the process until your point of aim and point of impact are aligned.
  5. Once you have zeroed your scope at 20 yards, you can proceed to longer distances (30, 40, 50 yards, etc.) to further refine your zero and become familiar with your scope's holdover points (BDC reticle) or mil-dots (if applicable).

A few additional tips:

  • Always use the same type of bolts and broadheads during the sighting-in process that you plan to use while hunting or shooting.
  • Be patient and take your time while adjusting your crossbow scope. It may take several attempts to get your scope dialed in correctly.
  • Regularly check your crossbow's components, such as string, cables, and limbs, for wear and tear to ensure consistent performance.

By following these steps and practicing regularly, you'll be able to adjust and use your crossbow scope effectively, leading to improved accuracy and success in the field.

Troubleshooting Common Crossbow Scope Issues

Occasionally, you may encounter issues with your crossbow scope that affect accuracy or performance. Here are some common crossbow scope issues and tips for troubleshooting them:

Inconsistent groupings:

  • Ensure that your crossbow is properly maintained, with a well-tuned string, cables, and limbs. Replace any worn components as needed.
  • Check your shooting technique and practice consistently to improve your skills.
  • Make sure your scope is securely mounted and the bolts are tightened evenly. Avoid over-tightening, which could damage the scope.
  • Use the same type and weight of bolts and broadheads for both sighting-in and shooting.

Difficulty zeroing the scope:

  • Double-check the mounting of the scope to ensure it is properly seated and aligned on the crossbow rail.
  • When adjusting the windage and elevation knobs, make small, incremental changes, and track the impact of each adjustment.
  • Verify that your scope's click values (MOA or MRAD) are correctly understood and applied when making adjustments.

Parallax issues:

  • If your scope has a parallax adjustment feature, use it to correct for parallax at different shooting distances.
  • Maintain a consistent cheek weld and eye position behind the scope to minimize parallax error.

Limited visibility or poor image quality:

  • Keep your scope's lenses clean and free from dirt, dust, and fingerprints.
  • Check that the scope's ocular and objective lenses are properly focused and adjusted for your eyesight.
  • If your scope has an adjustable magnification, experiment with different magnification levels to find the best balance between field of view, brightness, and image clarity.

Illuminated reticle issues:

  • Ensure the batteries are properly installed and have sufficient charge.
  • Check that the illumination settings are correctly adjusted according to the lighting conditions.
  • Consult the scope's manual to determine if the reticle is user-serviceable. If not, contact the manufacturer for assistance.

Loose or shifting scope:

  • Regularly inspect and tighten the scope rings and mounting bolts to ensure a secure fit.
  • If the issue persists, consider using higher quality scope rings or a single-piece scope mount to enhance stability.

Remember that regular maintenance, proper mounting, and sighting-in are crucial for optimal crossbow scope performance. If you continue to experience issues despite troubleshooting, consult your scope's owner's manual or contact the manufacturer for further guidance or service.

Maintaining Your Crossbow Scope for Optimal Performance

Maintaining your crossbow scope is essential to ensure optimal performance, accuracy, and longevity. Here are some tips to help you care for and maintain your crossbow scope:

  1. Clean the lenses: Keep the scope's lenses clean and free from dirt, dust, and fingerprints. Use a lens brush or a soft, lint-free cloth to gently remove debris. For smudges or tougher stains, use a lens cleaning solution specifically designed for optical lenses. Avoid using harsh chemicals or abrasive materials that could damage the lens coatings.
  2. Inspect mounting hardware: Regularly inspect the scope rings and mounting bolts for signs of wear, damage, or loosening. Tighten any loose bolts and consider replacing worn or damaged hardware as needed. When tightening the bolts, do not overtighten them, as this could damage the scope.
  3. Protect the scope: When not in use, cover the scope's lenses with lens caps to protect them from dust, moisture, and scratches. If your crossbow scope has a removable battery for illumination, consider removing the battery before long-term storage to avoid leakage and corrosion.
  4. Store in a controlled environment: Store your crossbow and scope in a dry, temperature-controlled environment, away from direct sunlight or extreme temperature fluctuations. Excessive moisture or heat can damage the scope's internal components and compromise its performance.
  5. Check for proper focus: Regularly check the ocular and objective lens focus to ensure they are correctly adjusted for your eyesight. Adjust the focus as needed for optimal image clarity and sharpness.
  6. Periodically re-zero: Over time, your scope's zero may shift due to use, transportation, or minor adjustments. Periodically re-zero your crossbow scope to ensure consistent accuracy.
  7. Avoid disassembling the scope: Most crossbow scopes are sealed and filled with inert gas to prevent internal fogging and maintain waterproof integrity. Disassembling the scope can compromise these features and potentially damage the internal components. If you suspect a problem with your scope that cannot be resolved through regular maintenance, contact the manufacturer or a professional gunsmith for assistance.

By following these maintenance tips and practicing proper care, you can help ensure that your crossbow scope remains in optimal working condition, providing you with reliable and accurate performance for years to come.


In conclusion, understanding and maintaining your crossbow scope is essential for optimal performance, accuracy, and safety. Familiarize yourself with the various types of reticles and learn how to make the necessary adjustments to windage, elevation, parallax, and magnification. Properly mounting and sighting-in your crossbow scope is crucial for achieving consistent accuracy.

Troubleshooting common crossbow scope issues, such as inconsistent groupings, difficulty zeroing, and limited visibility, can help you address and resolve any problems that may arise. Regular maintenance, including cleaning the lenses, inspecting the mounting hardware, and protecting the scope from damage, ensures the longevity and reliability of your crossbow scope.

By following these guidelines and tips, you'll be better equipped to utilize your crossbow scope effectively, leading to improved accuracy and success in the field or on the range.