Building your own AR-15 lower receiver is a rewarding experience for firearms enthusiasts. It allows for customization, a deeper understanding of your firearm, and often, significant cost savings compared to buying a complete rifle. However, navigating the world of AR-15 lower build kits can be daunting for beginners. This comprehensive guide will walk you through everything you need to know, from choosing the right kit to successfully completing your build.
Understanding the AR-15 Lower Receiver
The lower receiver is the serialized part of the AR-15, considered the firearm itself by the ATF. It houses the fire control group (trigger, hammer, disconnector, etc.), the magazine well, and the buffer tube. A lower parts kit (LPK) contains all the necessary components to complete the lower receiver.
Choosing the Right AR-15 Lower Build Kit
The market offers a wide array of AR-15 lower build kits, catering to various budgets and preferences. Consider these factors when making your selection:
1. Budget:
Prices vary significantly depending on the brand, materials, and included components. Entry-level kits are affordable, while higher-end kits may feature enhanced materials or features.
2. Manufacturer Reputation:
Opt for reputable manufacturers known for producing high-quality, reliable components. Research reviews and compare different brands before making a decision.
3. Included Components:
Some kits include only the essential parts, while others may offer additional components like enhanced triggers or buffer tubes. Carefully review the kit's contents to ensure it includes everything you need.
4. Material Quality:
The lower receiver itself is typically made from aluminum or polymer. Aluminum is more durable and preferred by many builders, while polymer offers a lighter weight option.
Essential Components of an AR-15 Lower Parts Kit (LPK)
A complete LPK typically includes:
- Trigger: The mechanism that initiates the firing sequence.
- Hammer: Strikes the firing pin to ignite the cartridge.
- Disconnector: Prevents automatic firing.
- Firing Pin Retaining Pin: Secures the firing pin.
- Firing Pin: Ignites the primer.
- Bolt Catch: Locks the bolt open after the last round is fired.
- Bolt Catch Roll Pin: Secures the bolt catch.
- Magazine Catch: Releases the magazine.
- Magazine Catch Roll Pin: Secures the magazine catch.
- Lower Parts Kit Pins: Various pins to assemble the lower receiver.
- Grip Screw: Secures the pistol grip.
- Buffer Retainer Pin: Secures the buffer retainer.
- Buffer Tube: Houses the buffer spring and buffer. (Often sold separately.)
Tools Needed for AR-15 Lower Build
You'll need a few specialized tools for a successful build:
- AR-15 Lower Receiver Vise Block: Securely holds the lower receiver during assembly.
- Roll Pin Punch Set: Various sizes for installing and removing roll pins.
- Hammer: A standard hammer will suffice.
- Screwdriver: A standard Phillips head screwdriver.
Step-by-Step AR-15 Lower Build Process
While specific instructions may vary slightly depending on the kit, the general process remains consistent:
- Prepare the Lower Receiver: Ensure it's clean and free of debris.
- Install the Trigger and Hammer Pins: Use the roll pin punch to carefully install these pins.
- Install the Trigger and Hammer: Insert the trigger and hammer into their respective positions.
- Install the Disconnector: Position and install the disconnector.
- Install the Bolt Catch and its Pin: Carefully insert and secure the bolt catch.
- Install the Magazine Catch and its Pin: Secure the magazine catch in its designated location.
- Install the Grip Screw: Secure the pistol grip.
- Install the Buffer Tube (if not pre-installed): Screw the buffer tube into the lower receiver.
- Install the Buffer Retainer Pin: Secure the buffer retainer.
- Double-Check Assembly: Carefully inspect all components to ensure proper installation and function.
Safety Precautions
- Always follow all local, state, and federal laws regarding firearm ownership and assembly.
- Handle firearms responsibly and safely.
- Never point a firearm at anything you do not intend to shoot.
- Keep firearms out of the reach of children.
- Consult a qualified gunsmith if you encounter any difficulties during the assembly process.
Building your own AR-15 lower receiver can be an enjoyable and educational experience. By following these steps and taking necessary safety precautions, you can successfully complete your build and enjoy your custom AR-15. Remember, responsible gun ownership is paramount.
