How to Assemble an AR-15 Lower: A Detailed Guide
Assembling an AR-15 lower receiver is a task that requires precision, patience, and a bit of know-how. Whether you’re a beginner or an experienced gunsmith, this guide will walk you through the process step by step. Before you begin, make sure you have all the necessary tools and parts. Here’s what you’ll need:
| Tool | Part |
|---|---|
| AR-15 lower receiver | Receiver group (including bolt, bolt carrier group, and firing pin) |
| Hex wrenches | Receiver pins |
| AR-15 lower receiver pin punch | Trigger assembly |
| Trigger group installation tool | Magazine catch |
| Magazine release spring | Magazine release button |
| AR-15 lower receiver installation tool | Handguard |
| Hex wrenches | Receiver extension |
| Hex wrenches | Receiver end plate |
Step 1: Prepare the Lower Receiver
Start by cleaning your lower receiver thoroughly. Remove any debris or oil that may have accumulated. Once it’s clean, inspect the receiver for any cracks or damage. If everything looks good, place the receiver on a flat, stable surface.
Step 2: Install the Receiver Group
Begin by installing the receiver group. This includes the bolt, bolt carrier group, and firing pin. Make sure the bolt is fully seated in the receiver and that the firing pin is properly installed. Next, install the bolt carrier group, ensuring that the bolt is fully engaged with the carrier.
Step 3: Install the Trigger Assembly
Using your trigger group installation tool, install the trigger assembly. Make sure the trigger is properly seated and that the hammer and sear are engaged. Once the trigger assembly is in place, install the hammer and sear spring.
Step 4: Install the Magazine Catch
Attach the magazine catch to the lower receiver using the magazine catch spring and the magazine catch pin. Make sure the magazine catch is securely fastened and that the magazine release button is properly installed.
Step 5: Install the Handguard
Slide the handguard onto the receiver extension tube. Make sure it’s properly aligned and securely fastened. Next, install the receiver end plate using the appropriate hex wrench.
Step 6: Install the Receiver Extension
Attach the receiver extension to the lower receiver using the receiver extension pin and the appropriate hex wrench. Make sure the receiver extension is securely fastened and that the bolt catch is properly installed.
Step 7: Final Inspection
Before you start shooting, perform a final inspection of your assembled AR-15 lower receiver. Check all the components to ensure they are properly installed and functioning. Make sure the magazine release works smoothly and that the bolt carrier group moves freely.
Once you’re confident that everything is in order, you can proceed to assemble the upper receiver and complete your AR-15 build. Remember to always follow safety guidelines and consult a professional if you’re unsure about any part of the process.