The AR 15 is known for its high degree of modularity, which might give beginners a difficult experience in assembling the AR 15 lower receiver.
When I was a beginner, I remember struggling to put everything together. I thought it was impossible.
However, there’s no reason to fear because I will show you how to build an AR 15 lower receiver in the simplest way possible!
Contents
Building an AR-15 Lower Receiver: Step-by-Step Process
Step 1: Assemble the Required Tools
The basic tools needed to build an AR 15 lower receiver are:
- Brass Punch and Punch set
- Hammer (preferably small brass type)
- Hex Wrench (preferably t-handle type) or Flat Head Screw Driver depending on the type of Pistol Grip Screw
- Castle Nut wrench for collapsible stocks
- Multi-tools
- Needle nose pliers
- AR 15 Lower Receiver Fixture
- Optional Tools: Small Magnetic Parts Dishes
Step 2: Front Pivot Pin Assembly
There are many ways you can start with the assembly of your AR 15 lower receiver.
However, I find it easier in this guide to start with the hardest part of the build, which is the front pivot pin assembly.
To distinguish the front pivot pin from the rear takedown pin, remember that the front pivot pin is longer than the rear takedown pin.
It might be a little bit tough to distinguish one takedown pin from the other, but their corresponding springs are just identical, and you can use both springs for either of the pins.
Installing the Spring and Detent
- Start by dropping the pivot detent spring into the small hole in the upper right of the AR 15 lower receiver.
- Take the pivot pin detent and your punch.
- Both have approximately the SAME DIAMETER.
- Press the pivot pin detent into the hole with your thumb on top of the spring.
- Do this step cautiously or else you might lose your detent.
- Press the tool through the left part until the detent sticks to your punch.
Do these steps cautiously because your detent might fly away to some obscure area if you forcefully push it while the detent still hasn’t stuck to the tool.
This would be difficult to find as it is a tiny component of your AR 15 rifle.
Laying Down the AR 15 Lower Receiver
This will give you an easier time finding the pin once it shoots out.
Carefully push against the protruding punch using your front pivot pin until the detent connects to the pivot pin.
The detent should be fully secure to the pivot pin.
Your detent should make a clicking sound and penetrate the holes and bottom of the pin.
If these happen, you would have successfully attached the front pivot pin to your AR 15 rifle!
Step 3: Magazine Catch Assembly
Next, let’s go on and assemble the magazine catch assembly guide.
Drop the mag catch on the left part of the AR 15 lower receiver. The magazine catch should fit snugly into the space.
When you take a look at the right part, you should see the screw sticking out through the other side.
Drop the magazine catch spring over the screw and then secure the magazine release button onto the screw by turning it sufficiently to make it hold on.
Press down the button to turn the AR 15 lower receiver over.
Be sure to grab hold of the magazine catch on the other side of the AR 15 lower receiver to turn it around.
You should turn the magazine catch around 3 TIMES.
Depressing the Magazine Release Button
Use a punch to press down on the magazine release button, press down the button completely into the AR 15 lower receiver body.
Twist the magazine catch until you feel strong resistance from the magazine catch spring.
Test the magazine catch button to ensure that the magazine catch COMPLETELY LEAVES the magazine sufficiently.
Now, you have now done the magazine catch assembly.
Step 4: Bolt Catch Assembly
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