A Comprehensive Guide to Building and Safely Using an AR-15 Lower Receiver

The AR-15 platform has gained immense popularity for its modularity and customization options. One key aspect of building an AR-15 is assembling the lower receiver, which houses the trigger assembly. In this guide, we’ll walk you through the process, from gathering tools and materials to understanding legal considerations, and finally, the step-by-step assembly process.

Section 1: Gathering Necessary Tools and Materials

Building an AR-15 lower receiver requires specific tools and materials. Here’s a comprehensive list:

Tools:

• Vise
• Hammer
• Punch set
• Flathead screwdriver
• 3/8-inch drive ratchet and socket set
• File

Materials:

• Lower receiver
• Lower receiver parts kit
• Upper receiver
• Barrel
• Bolt carrier group
• Charging handle
• Rifle buffer tube, buffer, and spring

Section 2: Legal Considerations and Regulations

Before embarking on this project, it’s crucial to understand the legal aspects of firearm ownership. Familiarize yourself with the laws in your state regarding possession, sale, transfer, and manufacture of firearms.

Section 3: Step-by-Step Assembly Process

Follow these steps to build your AR-15 lower receiver:

1. Removing Pistol Grip:

   • Use a hammer and punch to drive out the trigger guard pins.
   • Once the pins are out, remove the pistol grip by pulling it straight off the receiver.

2. Installing Buffer Tube:

   • Use a ratchet and socket to remove the buffer tube screw.
   • Insert the buffer tube into the receiver and secure it.

3. Installing Buffer and Buffer Spring:

   • Insert the buffer into the buffer tube.
   • Install the buffer spring over the buffer.

4. Installing Trigger Guard:

   • Use a screwdriver to remove the screws holding the trigger guard in place.
   • Insert the trigger guard and secure it.

5. Installing Trigger:

   • Use a screwdriver to remove the screws holding the trigger in place.
   • Insert the trigger and secure it.

6. Installing Selector Switch:

   • Use a screwdriver to remove the screws holding the selector switch in place.
   • Insert the selector switch and secure it.

7. Installing Bolt Catch:

   • Use a screwdriver to remove the bolt catch screw.
   • Insert the bolt catch and secure it.

8. Installing Magazine Catch:

   • Use a screwdriver to remove the magazine catch screw.
   • Insert the magazine catch and secure it.

9. Testing the Lower Receiver:

   • Insert a magazine and pull the charging handle.
   • Ensure the bolt moves forward, and the hammer falls. If not, recheck your assembly.

Conclusion:

Building an AR-15 lower receiver is a rewarding project for firearm enthusiasts, but it must be approached with caution and a thorough understanding of the legal implications. By following the steps outlined in this guide, you can safely and successfully assemble your AR-15 lower receiver. Remember, always prioritize safety and adhere to local laws and regulations.