Assemble Bolt Carrier Group

How to Assemble Bolt Carrier Group?

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Assemble Bolt Carrier Group

The Bolt Carrier Group (BCG) is very significant in the respective guns that use it. It enhances the semi-automatic functioning of a gun when a trigger is pulled by allowing the firing pin to strike the already chambered round’s primer. It also serves other critical functions, such as holding the spent cartridge casing to be ejected out of the chamber and chambering the next round into the chamber to be fired. Finally, it responsible for re-cocking the hammer for the next round from the magazine.

This article is a guide on the parts of the BCG and how you should assemble those parts to come up with a complete assembly.

Tools Needed to Assemble the BCG

  • Punch Set
  • A vise
  • Allen wrenches
  • Needle-nose pliers
  • Nylon/brass hammer
Assemble Bolt Carrier Group
Assemble Bolt Carrier Group

Components Needed to Make a BCG Assembly

  • A bolt carrier
  • Gas key
  • Gas key screws
  • Gas rings
  • Firing pin
  • Cam pin
  • Firing pin retaining pin
  • Bolt
  • Ejector
  • Ejector roll pin
  • Ejector spring
  • Extractor
  • Extractor pin
  • Extractor spring
  • Extractor spring insert

Once you have the right tools and necessary components, you can start the process of assembling.

A step by step Guide on how to Assemble a Bolt Carrier Group

  • Start by setting up your Bolt on the vise.
  • Insert the Ejector spring into its hole next to the Firing pinhole.
  • Drive in the ejector roll pin using punch roll from your set and the Nylon/Brass hammer. However, it requires a little bit of hammering to leave a passage for the ejector.
  • Drop in the ejector. The part of the ejector with a cutting should face the ejector roll pin.
  • Now finish up on the ejector pin by driving it completely using the same tools you used starting it.
  • Position your Extractor Spring Insert into the Extractor Spring. The spring should be inserted from the big side of the spring.
  • Then install the above assembly in its place in the Extractor. The large side of the assembly goes into the Extractor.
  • Use a needle-nose plier to press the assembly against the Extractor until you hear the insert click into its position.
  • Install the above Extractor assembly to its place in the Bolt. Also, insert a pin to tighten them together.
  • Proceed and insert your Gas rings into the narrow end of the Bolt.
  • Carefully roll the Gas Rings using your fingers to avoid any possible damage that could cause a gas leak. Also, ensure there is an even gap between the Gas Rings.
  • Now, it’s time to work on your Carrier.
  • Position your gas key on the Carrier and drive in Gas Key screws into their slots. Use your Allen Wrench to tighten up the screws.
  • Then install your Bolt assembly into the Carrier. The side of the Bolt Assembly with the two holes allows you to insert the Cam pin. That side should be aligned with the cam pin slot on your Carrier.
  • Insert your Cam pin horizontally.
  • Then use your roll pin punch to turn the Cam Pin to a 90-degree angle as it gets into position.
  • Insert your firing pin into its position in the assembly.
  • Then install your retaining pin and turn the Bolt Carrier upside down to confirm whether the firing pin is intact.
  • Now, you have a complete Bolt Carrier Group ready to be installed into your Upper Receiver.

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Assembling your Bolt Carrier Group is not a complicated process when you have the right tools at hand and all parts on your table. The above guide will help you from the start till you complete the assembly ready for installation. Visit custom firearms for more information.

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