How To Mount A Scope On An AR

Published on May 13, 2026
Duration: 22:47

This guide details how to properly mount a scope on an AR-15, emphasizing critical steps like achieving correct eye relief, ensuring the mount is secured only to the upper receiver, and achieving a level reticle using specialized tools. It covers the importance of using cantilever mounts for AR platforms and provides a detailed process for leveling the optic to the bore, followed by torquing procedures and a practical method for bore sighting without specialized tools.

Quick Summary

Properly mounting a scope on an AR-15 involves achieving correct eye relief by adjusting scope position for a full field of view, using a cantilever mount for proper height, and critically leveling the optic's reticle to the bore using a specialized tool like the Aerosaka scope leveler. Always torque screws to manufacturer specifications.

Chapters

  1. 00:11Introduction: Mounting an AR-15 Scope
  2. 01:34AR-15 Specific Mounts: Cantilever vs. Traditional
  3. 02:02Mounting Location: Upper Receiver Only
  4. 02:49Choosing the Right Mount and Rings
  5. 04:08Determining Scope Placement: Eye Relief
  6. 05:55Preparing for Mounting: Vise and Vice Block
  7. 06:18Initial Mount Installation and Torquing
  8. 08:34Preparing for Scope Installation: Loosening Rings
  9. 09:19Placing the Scope in the Rings
  10. 10:00Checking Ring Clearance and Alignment
  11. 11:01Ensuring Even Ring Gaps
  12. 12:53Scope Leveling: Importance and Methods
  13. 13:47Using the Aerosaka Scope Leveler
  14. 17:16Torquing the Scope Rings
  15. 19:19Final Checks and Visual Inspection
  16. 20:10Bore Sighting the Optic
  17. 21:45Conclusion and Final Tips

Frequently Asked Questions

What is the most critical factor when determining where to place a scope on an AR-15?

The most critical factor is eye relief. You need to position the scope so that when you assume a comfortable shooting stance, you can see a full field of view through the optic without straining your eye or having the scope physically contact your face.

Why are cantilever scope mounts preferred for AR-15 platforms?

AR-15s have a higher stock position relative to the upper receiver compared to traditional rifles. Cantilever mounts extend forward, providing the necessary height and distance to achieve a proper cheek weld and sight picture without forcing the shooter into an uncomfortable position.

What is the best method for leveling a scope on an AR-15?

The most reliable method is using a dedicated scope leveling tool, like the Aerosaka scope leveler, which interfaces with the flat surfaces of the scope mount and the scope body to ensure the reticle is perfectly parallel to the bore. Avoid using levels on turret caps.

What are the recommended torque specifications for mounting a scope on an AR-15?

Torque specifications vary by manufacturer. For the mount base, 65 inch-lbs is common, while scope ring screws are typically torqued to around 25 inch-lbs. Always consult your specific mount's manual for precise values.

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