An Ultimate Guide On How To Build An AR-15 Upper Receiver

An Ultimate Guide On How to Build an AR-15 Upper Receiver

If you’re putting together an AR-15 upper receiver on your own to get the full experience, no worries – this guide will go over everything you need to know. Let’s get started.

Building an AR-15 Upper Receiver

Collect the Parts and Tools

All AR-15 upper receivers come with a series of parts that might differ depending on the purpose of your build.

For instance, competitive target shooting AR-15 upper receivers will use different parts and components compared to plinking or casual shooting receivers.

But any type of AR-15 will need the following parts:

  • The receiver itself. These can come either stripped or fully assembled. We’d recommend getting a receiver with a forward assist already built-in, particularly if you are a beginner
  • A barrel
  • A handguard
  • A bolt control group or BCG
  • A gas block
  • A charging handle
  • A gas tube

You’ll also need a handful of tools to ensure the installation goes smoothly. These include:

  • An upper receiver block. This allows you to install the barrel without damaging it
  • A vice which holds parts in place
  • A punch set
  • A hammer or rubber mallet
  • A ½ inch torque wrench
  • A wheeler torque wrench
  • An AR-15 combo tool
  • A feeler gauge
  • A headspace gauge

Now let’s break down the process to build an AR-15 upper receiver step-by-step.

Step 1: Assemble the AR-15 Upper Receiver


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Skip this step if you have an assembled upper receiver component.

First, put your upper receiver in your vice’s block and either install the forward assist or, if it’s already installed, make sure that the FA’s tooth/teeth are facing toward the receiver itself.

Place the vice block into the vice – it’s also a good idea to place a small towel beneath the receiver unit to stop the vice from scratching its surface.

Make sure the FA is in position, then tap the roll pin with one of your punches.

Step 2: Insert the Pin

Press down on the forward assist while you are inserting the pin.

This will cause the raised part to get caught by the pin and ensures that the receiver component stays in place.

Use the punch to ensure the parts are snug and secure together.

Step 3: Place the Ejection Port


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Time for the ejection port. Use pliers to install the C-shaped snap ring or, if you’re lucky, the pin might already have the snap ring installed.

Place the ejection port properly and slide your hinge pin so it points toward the exposed and middle area of the receiver.

Twist the long end of the pin 180° and point it toward the table. Push your rod through the middle of the receiver.

Step 4: Install the Barrel

It’s time for the gas block and barrel. This should simply slide into place without much effort or you might have a barrel that already has a gas block installed.

To install the barrel, use your index pin and fit it into the receiver.

You can use a little bit of gun oil to make everything slide around more easily. Take your barrel not, put it on the barrel, and install.

Use the torque wrench to make sure that the nut is tightened correctly.

Find your gas block and gas tube – install the gas block first by finding the larger hole for the tube.

Make sure that, when you install the gas block, the larger hole is face down so that each opening matches up correctly.

Take the roll pin and use pliers to compress one end.

You should be able to fit the gas tube on relatively easily, but use a hammer to tap it if necessary.

Use the vice to hold everything in place. The gas tube should slide easily over the barrel.

Make sure that it aligns properly. Your barrel should have some words perfect for matching together.

You can use your Wheeler torque wrench set to 35 in-lb to make sure that your torque is even all the way around.

Step 5: Install the Handguard


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Install your handguard by slotting it into place on the receiver.

Double-check to make sure everything is aligned properly.

Your index pin should be totally flush at the bottom of the receiver.

Step 6: Add Muzzle Attachments

At this point, you can add muzzle attachments or other devices if necessary.

You’ll also want to thoroughly lubricate most of the parts, but especially the bolt carrier group, to ensure proper functionality.

This is a streamlined overview for building an AR-15 upper receiver.

You may have to tweak some of the steps here and there depending on the exact parts you purchase.

But overall, following these steps will result in a functional and customizable AR-15 upper receiver in no time at all!

Why do you like using an AR-15 upper receiver? Share your thoughts with us in the comments section!

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One Response to :
An Ultimate Guide On How To Build An AR-15 Upper Receiver

  1. Mitchell Bentley says:

    I cannot afford to be a member and pay my bills. signed patriot.

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