Tech Tip: SOLGW M89 Heavy Handguard Installation

Published on September 25, 2024
Duration: 12:29

This video provides a detailed, step-by-step guide for installing the Sons of Liberty Gunworks M89 Mark 10 Heavy Handguard on a large-frame AR-308 platform. It covers barrel nut installation, torque specifications, and the unique mounting system for the handguard, emphasizing proper alignment and avoiding overtightening. The installation is demonstrated on an Aero Precision upper receiver compatible with the DPMS High pattern.

Quick Summary

The SOLGW M89 Mark 10 Heavy Handguard is designed for large-frame .308 AR platforms and fits DPMS High pattern uppers. Installation involves torquing the barrel nut to 60 ft-lbs using a specific procedure and then securing the handguard with specialized fasteners, ensuring a hard stop is felt when tightening to prevent damage.

Chapters

  1. 00:00Introduction
  2. 00:32M89 Heavy vs. Standard M89
  3. 01:01AR-10 Upper Receiver Compatibility (DPMS High)
  4. 01:34Tools and Materials
  5. 03:06Handguard Components Included
  6. 03:34Barrel Installation and Lubrication
  7. 04:17Barrel Nut Installation
  8. 04:46Barrel Nut Torque Procedure
  9. 06:29Gas Block and Tube Installation
  10. 07:15Handguard Alignment Pin Discussion
  11. 07:43Handguard Installation
  12. 07:59First Fastener Installation
  13. 08:53Specialized Nut and Bolt System
  14. 10:06Installing Remaining Fasteners
  15. 11:47Final Steps and Conclusion

Frequently Asked Questions

What is the primary difference between the SOLGW M89 Heavy Handguard and the standard M89?

The SOLGW M89 Heavy Handguard is specifically designed for the larger frame .308 AR platform, whereas the standard M89 is for the AR-15. The heavy version is also available with or without integrated ARCA rail.

What torque specification is used for the barrel nut when installing the SOLGW M89 Heavy Handguard?

The barrel nut for the SOLGW M89 Heavy Handguard is torqued to 60 ft-lbs. A specific procedure involving tightening, backing off, and repeating is recommended to properly marry the threads.

How do you properly install the specialized nuts for the SOLGW M89 Heavy Handguard?

The specialized nuts have a beveled side and a flat. The bevel must face inward, and the flat side aligns with the corresponding flat on the handguard's mounting point. Tighten until a hard stop is felt, then stop to avoid damage.

What type of AR-10 upper receiver is compatible with the SOLGW M89 Mark 10 Heavy Handguard?

The SOLGW M89 Mark 10 Heavy Handguard is compatible with DPMS High pattern AR-10/.308 upper receivers, which are characterized by a taller rail height over bore compared to standard AR-15 uppers.

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