Firearm assembly may not be a beloved hobby for many, but it’s certainly worth the experience!
I’ll be teaching how to build an AR-15 upper receiver, which is something every gun owner should try to learn about.
While there may be a lot of things to learn, tools to get, and parts to decide on, it’s all part of the fun of the build!
In the end, you’ll be glad you tried it. I know I am!
I must warn you that if you are a beginner, there will be a lot of confusing terms, so I suggest having a professional help you out.
God knows I needed the extra hand.
Contents
What Is an AR Upper Receiver?
For the newbies out there, all this technical information on an AR 15 upper receiver can be overwhelming to learn.
Before I start on the process of building one, you need to know what an AR 15’s upper receiver is and what it does.
Your rifle is formed by TWO main parts: your upper and lower receivers.
Your AR 15 upper receiver is made up of multiple parts that you will be building one by one in this guide.
The main purpose of an upper receiver is to house the bolt and connect it to the barrel.
It also helps determine weight, accuracy, and overall performance of the rifle.
The upper receiver group is FULLY CUSTOMIZABLE, depending on your intended use, budget, preference, and more.
While you can choose to buy one that is fully assembled, you can also build it from scratch.
Types of AR Uppers
There are 4 types of AR 15 uppers you can get.
The A1 is the original model for AR 15. These have a light profile barrel, forward assists, and fixed carry handle.
They also include a flip rear sight for elevation and come equipped with short and long-range apertures. They can be accurate up to 450 yards.
The A2 receiver is a step up from the A1. Its elevation can be adjusted up to 600 yards and can consider windage.
I also have a full A2 sights removal guide if you’re interested.
The A3 has a flat top configuration and detachable carrying handle along with a rail and even high rise configuration.
Finally, the A4 uses M4 style feed ramps. These are the most common models available today.
What You’ll Need to Build an AR 15 Rifle Receiver:
Before you start building your upper receiver for the AR 15, you must have the right tools with you.
Pay attention to the list in this guide and make sure you get everything that may currently be missing from your tools.
Parts
- Upper Receiver (stripped or fully assembled)
- Barrel
- Hand guard or rail
- Bolt Carrier Group or BCG
- Gas block
- Charging handle
- Gas tube
Tools
- Brass or nylon hammer
- Universal Bench Block
- Allen Wrenches
- Needle Nose Pliers
- Roll Pin Punch Set
- Vise, w/ Soft Jaws
- AR Lower Receiver Vise Block
- Standard Punch Set
- Wheeler Torque Wrench
- Sunex 97738 1/2-Inch Drive Jumbo Crowfoot Wrench
- AR Armorer’s Wrench
- Gun oil or grease
- Crush washer
Steps for Building an AR 15 Upper Receiver
Step 1: Install Your Forward Assist
What You’ll Need:
- Upper Receiver
- Forward Assist (FA)
- FA Spring
- FA Roll Pin
- Universal bench block
- Armorer’s hammer
- Standard punch or 3-1/2in. Roll pin punch (the latter is preferred)
You will only need to do this if you’re using a stripped upper receiver for your AR 15.
If you have one that is fully assembled, you can go straight to step 2 of this guide.
BEFORE YOU START THIS STEP: Put your forward assist on spring tension so you can drive your pin all the way into place.
Hopefully, when you release it, the upper receiver will capture the forward assist.
Afterward, follow the steps below:
- First, ensure the hook or tooth faces TOWARDS the receiver, with the hook part facing inside (away from you or towards the table).
- Next, put a piece of cloth or paper towel in the vice to avoid any marring then place the block with the upper receiver on here.
- Ensure the forward assist is already inserted in the spring. Now it’s time to carefully put the forward assist in the correct position.
- When you’ve got it, TAP the roll pin with a punch.
- Make sure to press the forward assist in while you’re inserting the pin to ensure the raised part is caught by the pin and kept in place.
- Ask for assistance to hold the forward assist in place.
- If you’re on your own, hold the forward assist in with your thumb while keeping the punch between your index and middle finger to hammer in the pin.
- Use the hammer to lightly tap on the pin far enough that it won’t come off your forward assist.
- Finally, finish everything with the punch.
Step 2: Install the AR 15 Dust Cover
