How to Assemble an AR15 Bolt

The bolt on an AR-15 is the single most critical assembly on the rifle. It is the heart of the weapon, which enables the chambering and firing of ammunition and extraction of spent casings. After you've disassembled the bolt for a detailed cleaning, it's extremely important to correctly reassemble the bolt. Incorrectly replacing the bolt cam pin, in particular, will allow the rifle to chamber and fire a round, but may cause a chamber explosion.

Things You'll Need

  • Gunsmith's drift pin
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Instructions

    • 1

      Lay the bolt body on a sturdy work surface with the extractor housing facing up. Insert the extractor and extractor spring assembly into the housing, making sure the extractor's hinge aligns with the pin holes on either side of the bolt body.

    • 2

      Push in the extractor pin to secure the extractor. Make sure the ends of the pin are flush to the sides of the bolt. Use a drift pin or the tip of a bullet to push the extractor pin in all the way, if necessary.

    • 3

      Check the sealing rings on the back of the bolt to make sure there is space between each ring and the next. Then slide the bolt into the bolt carrier, with the extractor aligned to the carrier key on top of the bolt carrier.

    • 4

      Insert the bolt cam pin into the bolt carrier. Lock the bolt in place by turning the bolt cam pin a quarter-turn clockwise.

    • 5

      Slide the firing pin into the firing pin hole at the back of the bolt carrier. Grab the bolt by the locking lugs and pull it out of the bolt carrier until the cam pin engages.

    • 6

      Insert the firing pin retaining pin into the bolt carrier. Pull on the back of the firing pin to make sure it is locked in place and won't come out of the bolt carrier.