How to Install an Upper Barrel on an AR-15

The AR-15 rifle is a semiautomatic rifle that is the basis of the famed M-16 assault rifle, used by the U.S. Army. Though it was originally developed by Armalite, today several firms manufacture the AR-15. Its direct gas impingement system allows consistency from shot to shot, making it one of the most accurate semiautomatic rifles available on the market. The rifle is also extremely versatile, allowing for a number of upper receiver/barrel combinations, customizing the rifle for specific tasks. Even a new owner can learn to install an upper barrel.

Things You'll Need

  • Barrel wrench
  • Bench-mounted vise
  • Torque wrench with ½-inch drive
  • Antiseize compound or high-quality grease
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Instructions

    • 1

      Slide the action block insert into the receiver. This supports the receiver and keeps it from being altered during the installation.

    • 2

      Clamp the receiver into the block and insert both into the vise.

    • 3

      Clean the threads of the receiver, then cover them with the grease. To clean the threads, a damp rag or towel often does the trick.

    • 4

      Insert the barrel through the receiver from the front.

    • 5

      Thread the barrel nut onto the receiver with the wide end facing the rear.

    • 6

      Torque the nut to 35 foot-pounds with the torque wrench. Loosen, then repeat this.

    • 7

      Torque past 35 foot-pounds until the hole in the nut aligns with the gas tube hole in the receiver. Do not exceed 80 foot-pounds of torque.