How to Install a Stock on an AR15 Lower

Civilian AR15/M16-style rifles are sold by a variety of manufacturers and offer a range of optional stocks. Folding, collapsible and telescoping models are among the factory or aftermarket alternatives. The fixed, original equipment manufacturer A2 stock on the standard military AR15/M16 is basic and non-adjustable. Civilian AR15 shooters wishing to duplicate the no-frills authenticity of a government-issue M16 may choose to revert to the classic original A2 stock. The A2 stock installs on the lower receiver of the AR15 with just a screwdriver.

Things You'll Need

  • Slot screwdriver
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Instructions

    • 1

      Screw the long A2 buffer tube part of the way into the threads in the end of the AR15 lower receiver. Stop before the buffer tube obstructs the detent hole in the receiver's threads.

    • 2

      Insert the buffer detent spring into the detent hole in the threads, and place the buffer detent on top of the spring.

    • 3

      Depress the buffer detent down into its hole, compressing the spring. Turn the buffer tube a few more turns on the threads until it is secure against the buffer detent.

    • 4

      Insert the rear takedown pin into its hole in the right side of the lower receiver. Orient the takedown pin so the groove in it is facing toward the rear of the rifle.

    • 5

      Install the takedown detent into its small hole on the rear of the receiver below and to the right of the buffer tube. The takedown detent engages with the groove in the takedown pin. Insert the takedown detent spring into the hole after the detent.

    • 6

      Drop the plastic spacer ring down the buffer tube hole into the stock.

    • 7

      Slide the A2 stock over the buffer tube.

    • 8

      Screw the stock screw into the hole in the top of the end of the stock. Use a large slot screwdriver that fits tight into the slot; the screw is nylon coated and can be difficult to turn. Tighten until the stock is secured snugly to the buffer tube.

    • 9

      Place the recoil buffer into the end of the buffer spring.

    • 10

      Cock the hammer of the AR15. Insert the buffer spring into the buffer tube and push down on it, compressing the spring until the end of the recoil buffer travels past the buffer detent and locks in place.

    • 11

      Remove and replace the rear takedown pin to verify that it moves smoothly.