In recent years, the world of firearms enthusiasts has been captivated by the concept of 80% lowers. Whether you’re a hobbyist looking to build your own custom firearm or simply curious about what these lower receivers are, understanding the ins and outs of 80% lowers is essential. In this guide, we’ll break down everything you need to know about 80% lowers, from what they are and why they’re so popular, to the legal considerations and the process of completing one to build your own firearm.
What Are 80% Lowers?
An “80% lower” is a firearm receiver that is partially finished. Typically, the term is used to describe lower receivers for rifles, especially AR-15-style firearms. These lowers are about 80% completed, meaning they are missing critical machining operations, such as the fire control pocket or trigger pin holes, that make the part a fully functioning firearm. Because they are incomplete, they are not considered firearms under federal law, which makes them legal to purchase in many states without the need for a background check.
However, once the lower is completed—by drilling, milling, or other machining processes—it becomes a fully operational part of a firearm. At this point, it is subject to all the usual laws governing firearms, including serial number requirements and the need for background checks if you choose to sell or transfer it.
Why Are 80% Lowers So Popular?
- Legal Freedom: One of the primary reasons why 80% lowers are so popular is because they are not legally considered firearms. Federal law does not classify an 80% lower as a firearm because it lacks the necessary features to be considered “functional.” As a result, these lowers can often be purchased without the need for a background check in many states, making them an appealing choice for those who wish to avoid government regulation.
- Custom Builds: For firearm enthusiasts, 80% lowers provide the perfect platform for building a custom firearm. When you purchase an 80% lower, you can choose the rest of the components—such as the trigger, barrel, handguard, stock, and more—to fit your exact specifications. This level of customization is attractive to many who want a personalized firearm for self-defense, hunting, or shooting sports.
- Learning Experience: Many people enjoy the process of building a firearm from an 80% lower because it offers a valuable learning experience. Assembling a custom firearm from the ground up allows you to understand how the individual components interact and work together. It can be a highly educational process, particularly for those interested in mechanical work and gunsmithing.
- Cost Savings: While building a firearm from an 80% lower does require the purchase of additional parts and tools, it can often be more cost-effective than purchasing a fully assembled firearm. Many firearm enthusiasts find that building their own is not only cheaper but also more satisfying than buying a mass-produced model.
Legal Considerations of 80% Lowers
Although 80% lowers are not classified as firearms by federal law, this does not mean that they are free from all legal regulations. The legal status of 80% lowers depends on several factors, including where you live and what you intend to do with the completed firearm.
Federal Law
Under the Gun Control Act of 1968, a firearm is defined as a weapon that is “designed to or may readily be converted to expel a projectile by the action of an explosive.” Since 80% lowers are incomplete and cannot yet fire a projectile, they are not considered firearms until they are finished.
However, once you complete the 80% lower and it is capable of functioning as a firearm, it becomes subject to federal regulations. At this point, you must apply for a serial number (if required by state law) and follow all laws related to the manufacture, sale, or transfer of firearms.
State Laws
The legality of 80% lowers can vary from state to state. While federal law permits the purchase of 80% lowers without a background check, many states have more restrictive laws. Some states, such as California, New York, and New Jersey, have implemented strict regulations on 80% lowers. In these states, you may need to complete additional paperwork, undergo a background check, or serialize the lower once it’s finished.
It’s crucial to check your state’s specific regulations before purchasing an 80% lower, as you may be required to register the firearm or take other legal steps to remain compliant with local laws.
Serialization Requirements
Once you finish building your firearm, some states require that it be serialized. This means that you will need to engrave or apply a serial number to your completed firearm. While federal law does not mandate serialization for privately made firearms intended for personal use, states like California require it.
Failure to properly serialize a completed firearm can result in serious legal consequences, so be sure to verify the rules in your state before you start building.
How to Complete an 80% Lower
Completing an 80% lower requires some technical skills, tools, and patience. While it is certainly a DIY project, it’s not for beginners who aren’t comfortable working with machines. Here’s an overview of the process:
Step 1: Gather the Tools and Materials
Before you can begin completing your 80% lower, you’ll need the proper tools. Some of the necessary tools include:
- Drill press or milling machine: These are essential for drilling precise holes and milling the fire control pocket.
- 80% lower jig: A jig helps guide the drill and mill to ensure that you drill the right holes in the correct locations.
- Drill bits: A variety of sizes are needed to drill holes for the pins, safety selector, and trigger assembly.
- End mills: These are used to cut the fire control pocket and other sections of the lower receiver.
You will also need the lower receiver itself and the parts kit that will turn the lower into a complete firearm, such as the trigger, hammer, and magazine well.
Step 2: Attach the Lower to the Jig
The first step in completing the lower is to securely attach it to the jig. The jig serves as a guide that holds the lower in place while you drill and mill. It will ensure that your drilling and milling are accurate and aligned with the necessary parts of the lower receiver.
Step 3: Drill and Mill the Receiver
Once the jig is set up, you’ll begin the drilling and milling process. The fire control pocket is the most critical part to machine, as it will house the trigger mechanism. This is also the part where many beginners may make mistakes, so take your time and follow the instructions carefully. Drilling the pin holes for the trigger, hammer, and safety selector is also crucial to ensuring the firearm works properly.
Step 4: Clean Up and Finish the Lower
After drilling and milling, you’ll need to clean up the edges of the lower to remove any burrs or sharp edges. Depending on the finish you want, you can apply a protective coating, such as anodizing or cerakoting, to prevent rust and give the lower a finished look.
Step 5: Install the Parts Kit
Once your 80% lower is completed, you can begin installing the various components that make up the firearm, such as the trigger, hammer, magazine release, and stock. You will also need to attach the upper receiver, barrel, and other necessary parts to complete the firearm.
Advantages of 80% Lowers
1. Customization:
You can select the specific parts that best suit your needs, whether you want a lightweight build for tactical use or a heavier build for long-range shooting.
2. Cost Savings:
Building your own firearm from an 80% lower can often be less expensive than buying a pre-built firearm, especially if you already have the tools needed.
3. Privacy:
Purchasing an 80% lower typically doesn’t require a background check, which appeals to those who prefer to keep their firearm ownership private.
4. Learning Opportunity:
Completing an 80% lower allows you to gain a deeper understanding of how firearms work and improves your mechanical and gunsmithing skills.
Disadvantages of 80% Lowers
1. Legal Complexity:
The legality of 80% lowers can be confusing, as laws vary from state to state. It’s essential to stay informed about your state’s regulations.
2. Skill and Time:
Completing an 80% lower requires a certain level of skill and patience. The process can be challenging for those unfamiliar with tools and machinery.
3. Potential for Error:
Mistakes made during the machining process can result in a ruined lower receiver, which can be costly and time-consuming to replace.
Conclusion
80% lowers are a popular option for firearm enthusiasts who want to build a custom firearm while avoiding the restrictions associated with purchasing a fully completed firearm. While completing an 80% lower can be a rewarding experience, it does require technical skills, tools, and an understanding of legal regulations. If you’re interested in building your own firearm, be sure to research the process thoroughly, gather the right tools, and comply with your state’s laws. Whether you’re looking for a custom firearm or a new project to work on, 80% lowers offer a unique and fulfilling opportunity for firearm owners.
