How to Replace the Barrel on an ArmaLite AR-10

The ArmaLite AR-10 is an assault rifle capable of firing 7.62 mm rounds at a rate of 700 rounds per minute. The weapon was developed in 1956 by Eugene Stoner. The AR-10 uses a straight-line barrel design combined with lightweight composite materials. The weapon was significantly more lightweight and easier to control than other automatic assault rifles manufactured at the time. As with all weapons, periodic maintenance may be required from time to time including barrel replacement. Replacing the barrel on an AR-10 can be accomplished with little difficulty.

Things You'll Need

  • Cleaning rod
  • 1/8th-inch roll pin punch
  • Hammer
  • Padded barrel vise
  • Propane torch
  • AR-10 barrel lug wrench
  • Metal bonding solution (Blue LocTite recommended)
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Instructions

    • 1

      Remove the magazine. Pull the charging handle to the rear. Visually inspect the weapon to ensure no live ammunition is present.

    • 2

      Depress the rear take-down pin -- located above the handgrip -- from left to right using your thumb or knuckle. If the pin is stubborn, use a cleaning rod or other blunt ended object. Note the pin will not come completely out.

    • 3

      Hold onto the handgrip. Pivot the muzzle towards the ground, exposing the bolt inside the receiver. Slide out the charging handle along with the bolt carrier group from the receiver. Set the charging handle and bolt carrier group aside.

    • 4

      Push in the forward take-down pin located above the magazine well in the same manner as step 2. Separate the barrel and receiver from the weapon's frame.

    • 5

      Knock out the two pins on the front sight assembly with a 1/8-inch roll-pin punch and hammer. Pull the sight base and gas tube assembly forward and off the barrel.

    • 6

      Pull down on the handguard lock ring at the base of the plastic handguards. Pull off the handguards while holding the lock ring down. Rotate the handguard lock ring counterclockwise. Wiggle slightly then pull the lock ring off the barrel.

    • 7

      Secure the barrel and receiver into a padded barrel vise. Heat the barrel lug for 45 seconds using a propane torch. This will burn off the metal bonding solution used during manufacture.

    • 8

      Fit the barrel lug wrench onto the barrel lug nut. Turn the wrench counterclockwise until the barrel comes free from the receiver.

    • 9

      Apply metal bonding solution to the threading on the barrel lug. Apply only a light coat on the threads. ArmaLite recommends Blue LocTite for barrel assembly.

    • 10

      Screw the new barrel onto the barrel lug until hand tight. Use the barrel lug wrench to tighten the barrel to the proper position, lining up the lug grooves with the barrel grooves. Allow the barrel to sit undisturbed for 24 hours before reassembly and test firing.