How to Change an AR-15 Barrel: A Beginner's Guide

How to Change an AR-15 Barrel: A Beginner's Guide

Posted by Faxon Firearms Staff on Jul 29th 2024

Changing the barrel on your AR-15 can seem like a daunting task, but with the right tools and a bit of patience, it's a job that can be done in your own workshop. Whether you're looking to upgrade to a different caliber, replace a worn-out barrel, or simply customize your rifle, this guide will walk you through the process step by step.

Tools and Materials Needed

Before you begin, make sure you have the following tools and materials:

Safety First

Ensure your firearm is unloaded before starting. Remove the magazine and check the chamber to confirm there's no ammunition present. Safety glasses are also a good idea to protect your eyes from debris.

Step-by-Step Guide

1. Disassemble the Upper Receiver

  1. Remove the Handguard: Depending on your handguard type, you may need to remove screws, delta rings, or locking tabs. Slide the handguard off the upper receiver.
  2. Detach the Upper Receiver from the Lower: Push out the takedown and pivot pins to separate the upper receiver from the lower.
  3. Remove the Bolt Carrier Group and Charging Handle: Set these aside in a safe place.

2. Secure the Upper Receiver

Secure the upper receiver in a vise using an upper receiver block or reaction rod. This will prevent damage and keep the receiver steady while you work.

3. Remove the Old Barrel

  1. Remove the Flash Hider/Muzzle Device: Use an armorer's wrench to unscrew the flash hider or muzzle device.
  2. Remove the Gas Block and Gas Tube: Use a punch to drive out the roll pin securing the gas tube to the gas block, then slide the gas block and tube off the barrel.
  3. Remove the Barrel Nut: Use a barrel nut wrench to loosen and remove the barrel nut. This may require some force if it's been torqued down tightly or has anti-seize grease applied.

4. Install the New Barrel

  1. Prepare the New Barrel: Clean the barrel extension and the inside of the upper receiver with a degreaser. Apply a light coat of anti-seize grease to the barrel extension.
  2. Insert the New Barrel: Align the barrel extension with the upper receiver and slide it in place.
  3. Install the Barrel Nut: Thread the barrel nut onto the upper receiver and hand-tighten it. Use a torque wrench and barrel nut wrench to torque it to the manufacturer's recommended specifications (usually between 30-80 ft-lbs). Follow the pattern of tightening and loosening three times to properly seat the barrel nut.

5. Reinstall the Gas System

  1. Install the Gas Tube in the Gas Block: Slide the gas tube into the gas block and secure it with a roll pin using a starter punch and hammer.
  2. Install the Gas Block: Slide the gas block and tube assembly onto the barrel, aligning the gas port with the port on the barrel. Secure the gas block using set screws or a clamp (depending on your gas block type).

6. Reassemble the Upper Receiver

  1. Reattach the Flash Hider/Muzzle Device: Screw the flash hider or muzzle device back onto the barrel and tighten it with an armorer's wrench.
  2. Reinstall the Handguard: Slide the handguard back onto the upper receiver and secure it using the appropriate method for your handguard type.
  3. Reinstall the Bolt Carrier Group and Charging Handle: Slide the charging handle into the upper receiver, followed by the bolt carrier group.

7. Reassemble the Rifle

  1. Reattach the Upper to the Lower Receiver: Align the pivot and takedown pins and push them back into place to secure the upper receiver to the lower.

Final Checks

  1. Function Check: Perform a function check to ensure everything is working correctly. Check that the bolt carrier cycles smoothly, the charging handle operates correctly, and the trigger resets properly.
  2. Headspace Check: If you have the tools and knowledge, check the headspace to ensure the new barrel is within safe specifications.

Disclaimer

Always consult your manufacturer’s instructions and specifications before attempting any modifications or adjustments to your rifle. Ensuring compatibility and proper installation is crucial for safe operation. Failure to follow manufacturer guidelines may result in damage to the firearm or serious injury.

Conclusion

Changing the barrel on your AR-15 is a rewarding project that can improve your rifle's performance and longevity. By following these steps and using the right tools, you can successfully complete the job and enjoy the benefits of a custom AR-15. Always remember to prioritize safety and consult with a professional gunsmith if you're unsure about any part of the process. Happy shooting!

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