How to Tighten the Barrel on a DoubleStar AR-15

DoubleStar's Star-15 AR-15 is a mechanical duplicate of the AR-15/M-16 assault rifle issued by the United States military. The gas-operated, semi-automatic Star-15 fires .223 Remington/5.56 NATO ammunition with a muzzle velocity of 3,200 feet per second. Rounds are fed from 20- or 30-round box magazines where legal, or 10-round box magazines where the larger capacities are prohibited. It has a flat-top receiver with a detachable carrying handle and a 16-inch barrel. Sights are standard military iron sights. The loose barrel of a DoubleStar Star-15 AR-15 may be tightened by following the standard procedure for AR-15 barrel removal and installation.

Things You'll Need

  • AR-15 armorer's tool
  • AR-15 action block
  • Torque wrench
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Instructions

    • 1

      Mount the upper receiver of the AR-15 in a vise block (also known as an action block) and tighten the vise to hold it securely.

    • 2

      Remove the flash suppressor, sight riser, gas block and gas tube from the barrel. Remove the hand guards from the barrel.

    • 3

      Attach a torque wrench to the AR-15 armorer's tool. Tighten the barrel nut initially to 30 pounds of torque. Increasing torque approximately 10 pounds per turn, incrementally tighten the barrel nut to 80 pounds of torque.

    • 4

      Tighten once more at 80 pounds, just enough to align one of the gas tube holes in the barrel nut with the gas port in the receiver. Test the alignment with the gas tube to make sure it fits smoothly though the barrel nut port and into the receiver.

    • 5

      Reinstall the hand guards, gas block and gas tube, sight riser and flash suppressor on the barrel.