A Comprehensive Guide to 80 Lowers: Everything You Need to Know

The rise of 80 lowers in the firearm community has stirred a lot of interest among gun enthusiasts, hobbyists, and even first-time builders. While the concept of 80 lowers might sound a bit technical at first, understanding their appeal and the process of building a firearm from them is straightforward. Whether you’re a seasoned gunsmith or a DIY enthusiast looking to expand your knowledge, this guide will provide you with everything you need to know about 80 lowers.

What is an 80 Lower?

An 80% lower receiver is a partially completed firearm component, usually used in the construction of AR-15 or AR-10 rifles, although other platforms may have 80% lower receivers available. The name “80% lower” comes from the fact that it is 80% finished, meaning the receiver lacks key functional features such as the fire control pocket, pinholes, and trigger holes.

As a result, it cannot yet be legally classified as a firearm. In its unfinished state, the 80 lower is just a piece of metal or polymer. However, when you finish the necessary cuts and modifications, it becomes a functional lower receiver, which then qualifies as a firearm under the law.

Why Use an 80% Lower?

Building a firearm from an 80 lower can be an exciting and rewarding experience. There are several reasons why enthusiasts choose to take this route instead of purchasing a fully assembled firearm.

1. Customization and Personalization

One of the most compelling reasons for building a firearm from an 80 lower is the ability to fully customize the build to your specifications. When you start with an 80% lower, you can hand-pick every part of your firearm, from the handguard to the stock, trigger, and barrel. This degree of customization allows you to tailor the firearm to your specific needs, whether for sport shooting, hunting, or home defense.

2. Cost Savings

An 80 lower is often more affordable than buying a fully built firearm. Although you’ll need to purchase additional parts to complete the build, the overall cost is usually lower than that of a factory-made rifle. Many people choose this route as a way to save money on the build while still ending up with a high-quality firearm.

3. Educational Value

Building a firearm from an 80 lower is a hands-on project that teaches you valuable skills. You will learn about the mechanics of firearms, understand how different components work together, and gain experience with tools such as milling machines, drill presses, and jigs. This knowledge can be helpful for future projects, whether for repairing firearms or making modifications.

4. Satisfaction and Accomplishment

There’s a strong sense of pride and accomplishment that comes with completing a firearm from an 80 lower. The entire process, from starting with a blank slate to completing a functional firearm, is deeply satisfying. It allows you to see the results of your hard work and provides you with a unique, personalized firearm that you built yourself.

Legal Considerations: What You Need to Know

Before you begin building a firearm from an 80 lower, it’s crucial to understand the legal landscape surrounding them. While the purchase of an 80 lower is legal in many areas, you must adhere to certain rules and regulations to avoid legal issues down the line.

1. Federal Laws

At the federal level, an 80% lower is not classified as a firearm. This means that, in its unfinished state, it does not require background checks or registration. However, once you finish the 80 lower and complete it into a functional firearm, it becomes subject to federal firearms laws.

For example, when you build a firearm from an 80 lower, it must be for personal use. Selling or transferring firearms without going through a licensed dealer and conducting background checks is illegal under federal law.

2. State and Local Laws

While federal laws do not classify an 80 lower as a firearm, state and local laws may impose additional restrictions. Some states, like California, require individuals to register firearms built from 80 lowers or to apply serial numbers to the receiver. Other states have no such requirements, but it’s crucial to verify the specific regulations in your state.

Some states have also passed legislation specifically targeting 80 lowers to prevent the production of ghost guns (untraceable firearms). It’s essential to stay informed about your state’s regulations regarding the purchase, assembly, and possession of 80 lowers.

3. Serialization and Registration

Certain states mandate that you serialize your completed 80 lower. For example, California law requires that when you finish an 80% lower, it must be serialized and registered with the state. Even if the firearm is for personal use, you may need to complete a registration process.

It’s crucial to research and understand whether you need to serialize your build before starting the project. Keep in mind that federal law does not require serialization for personal use firearms unless the firearm is being sold or transferred.

4. Selling and Transferring Firearms

The legality of selling or transferring firearms built from 80 lowers is a complicated issue. In general, selling or transferring a firearm built from an 80 lower requires compliance with federal and state laws, including background checks and proper documentation.

If you intend to sell or transfer a firearm built from an 80 lower, you may need to involve a licensed firearms dealer to ensure compliance with the law. Without the proper steps in place, you could face legal consequences for attempting to sell a privately built firearm.

The Process of Completing an 80 Lower

To complete a 80 lower, you will need a few specialized tools and equipment. Here’s a general overview of the steps involved in finishing an 80 lower.

Step 1: Gather Your Tools and Equipment

To get started, you will need the following tools and equipment:

• Jig: A jig is essential for aligning the 80 lower properly during the milling process. It holds the lower receiver in place and ensures that you make the correct cuts.
• Drill Press or Milling Machine: These are the primary tools used to finish the 80 lower. A drill press is used for drilling holes, while a milling machine is used for more precise cuts, such as the fire control pocket.
• Drill Bits and End Mills: You’ll need a variety of drill bits for making holes and end mills for cutting the fire control pocket and other features.
• Safety Gear: Always use proper safety equipment, including safety glasses, hearing protection, and gloves when working with power tools.

Step 2: Install the Jig

The first step in finishing the 80 lower is to install the jig. The jig is a template that guides the cutting process and ensures that everything is aligned correctly. Follow the instructions provided with your jig to securely attach it to the 80 lower.

Step 3: Drill the Necessary Holes

Using your drill press, start by drilling the holes for the trigger, hammer, and other components. This step requires precision, so take your time and double-check your measurements.

Step 4: Mill the Fire Control Pocket

The next step is to mill the fire control pocket. This is the part of the lower receiver that holds the trigger group. Milling this pocket requires the use of a milling machine or an end mill, and it’s one of the most important steps in completing the 80 lower. Ensure the cuts are precise, as any errors in this area can lead to issues with the function of the firearm.

Step 5: Final Assembly

After the lower receiver is fully milled, it’s time to assemble the remaining parts, such as the buffer tube, stock, trigger, and other components. This step is straightforward, but be sure to follow the assembly instructions provided with your parts to ensure everything fits together correctly.

Common Mistakes to Avoid

While building a firearm from an 80 lower can be a rewarding experience, there are some common mistakes that beginners should avoid:

• Inaccurate Measurements: Precision is key when working with firearms. Ensure that you measure carefully before drilling or milling to avoid errors.
• Using Incorrect Tools: Always use the appropriate tools for the job. Using the wrong equipment can result in damage to your 80 lower or compromise the functionality of the firearm.
• Failing to Follow Legal Guidelines: Always check the laws in your state and locality before beginning your project. Failing to comply with legal requirements could result in serious legal consequences.

Conclusion

Building a firearm from an 80 lower is an exciting and rewarding experience for anyone interested in firearms, DIY projects, or custom builds. It offers the opportunity for customization, cost savings, and educational value. However, it is essential to be aware of the legal and technical aspects of the process.

Before starting your build, make sure to research the laws in your state and understand the requirements for completing, registering, and owning a firearm built from an 80 lower. By taking the time to properly complete your project and follow legal guidelines, you can enjoy a high-quality, personalized firearm built with your own hands.

Nieka Ranises