The Appeal of 80% Lowers: A Complete Guide to Building Custom Firearms
In the world of firearms, the 80% lower has emerged as a highly popular option for DIY enthusiasts, hobbyists, and gun builders looking to create custom firearms. The concept of 80% lowers has revolutionized the gun-building landscape, offering flexibility, creativity, and personalization. This blog will explore everything you need to know about 80% lowers, including their function, how to complete them, legal considerations, and why they’re becoming increasingly popular among gun builders and firearm enthusiasts.
What Is an 80% Lower?
An 80% lower is a firearm lower receiver that is 80% complete and requires the builder to finish the remaining 20%. While the lower receiver is one of the most critical components of a firearm, the 80% lower is considered “unfinished” because it lacks key machining features necessary for it to function as a firearm. These parts are sold as raw components that require further drilling and milling.
The process of turning an 80% lower into a functional firearm is often referred to as completing the lower, and it’s done by hobbyists using specific tools and a little know-how. This concept is popular because it allows the builder to have full control over the customization of the firearm, from choosing the exact parts to assembling it from the ground up.
Key Features of an 80% Lower:
- Not a firearm until completed: Since an 80% lower is not yet fully functional, it is not classified as a firearm according to federal law. This distinction makes it legal to purchase in many areas without the need for a background check or serial number.
- Requires finishing: The main task for completing an 80% lower is milling out the fire control pocket and drilling the necessary pin holes. A variety of tools, such as a drill press or milling machine, are needed to accomplish this.
- DIY custom firearms: The ability to assemble a firearm from scratch with your chosen parts is one of the biggest appeals of 80% lowers. It allows you to customize the weapon to suit your needs and preferences.
How Do 80% Lowers Work?
To complete an 80% lower, the builder needs to finish the remaining 20% of the machining work, which involves critical steps like drilling pin holes and milling the fire control pocket. The process can vary depending on the platform being built (e.g., AR-15, AR-10, etc.), but the basic steps for finishing an 80% lower are similar across different firearm models.
Step-by-Step Process of Completing an 80% Lower:
- Choose Your Tools:
- Drill Press or Milling Machine: A drill press or milling machine is essential for drilling holes and milling the fire control pocket with precision.
- Jig: A jig is a device used to securely hold the lower receiver in place while it is being worked on. The jig ensures that the holes and cuts are drilled in the correct locations.
- Clamps: To secure the jig and the 80% lower during the machining process.
- Set Up the Jig: The jig guides the process and helps position the lower receiver for accurate milling and drilling. Once the 80% lower is properly secured in the jig, it’s time to begin the machining work.
- Drill Pin Holes: The lower receiver must have specific holes drilled for the trigger, hammer, and safety pins. The jig typically includes a template that marks the proper hole locations for you.
- Mill the Fire Control Pocket: This step is the most critical in the finishing process. The fire control pocket is the area where the trigger mechanism and other components will be installed. Using a milling machine or drill press, you will cut the pocket to the proper dimensions, ensuring the mechanism fits correctly.
- Deburring and Finishing: After milling and drilling, the lower receiver will likely have sharp edges or rough spots that need smoothing. This step involves deburring the edges and ensuring the part is ready for assembly.
- Assemble the Firearm: After completing the 80% lower, you can begin assembling your firearm. This involves installing the trigger group, stock, and other necessary components to complete the build.
Legal Considerations: Is It Legal to Build a Firearm from an 80% Lower?
While 80% lowers are legal in many parts of the United States, it’s essential to understand the legal considerations surrounding them. The most significant factor in determining legality is whether the lower receiver is considered a firearm.
Federal Regulations:
At the federal level, the ATF (Bureau of Alcohol, Tobacco, Firearms and Explosives) does not classify an 80% lower as a firearm. This means that the purchase and possession of an 80% lower are legal without a background check or serial number. However, the moment you complete the lower and assemble it into a functioning firearm, it is considered a firearm under federal law. At this point, it must have a serial number and be subject to the same regulations as other firearms.
Important federal requirements include:
- Serialization: Once the 80% lower is completed and assembled, it must be serialized. In most cases, this involves marking the lower receiver with a serial number, which can be done by the builder or by visiting a licensed firearms dealer.
- Transfer and Sale: If you intend to sell the completed firearm, it must be properly serialized and transferred through an FFL (Federal Firearms License) dealer, who will conduct a background check on the buyer.
State Laws:
State laws vary significantly regarding 80% lowers. In some states, the purchase, completion, or sale of 80% lowers is heavily regulated or even illegal. States like California, New York, and New Jersey have stringent laws surrounding “ghost guns” (firearms built without serial numbers), which include 80% lowers.
Before building a firearm from an 80% lower, it’s essential to check your state’s laws to ensure you’re in compliance with all regulations. Some states require serialization for completed firearms, while others may have additional rules about registration or the types of firearms that can be legally built.
Advantages of 80% Lowers
For gun enthusiasts and those looking for a hands-on project, 80% lowers offer several benefits that make them a popular choice for DIY firearm builds.
1. Customization:
Building a firearm from an 80% lower allows you to customize every aspect of the weapon. You can select the components that suit your preferences, such as the trigger, grip, stock, and barrel, giving you a fully personalized firearm.
2. Learning Experience:
Completing an 80% lower is a valuable learning experience that helps you understand how firearms work. You’ll become familiar with the internal components and mechanics of the gun, which can be beneficial for repairs, maintenance, and troubleshooting.
3. Cost Savings:
In many cases, building a firearm from an 80% lower can be less expensive than buying a fully assembled firearm. While you may need to invest in tools initially, the cost of purchasing the components and assembling the firearm is often lower than purchasing a pre-built gun from a store.
4. Satisfaction:
There’s a sense of pride and satisfaction that comes from completing a firearm on your own. For many gun owners, the process of building a gun from scratch is highly rewarding, and the finished product feels more personal and unique.
5. Privacy:
Building a firearm from an 80% lower allows for greater privacy than purchasing a completed firearm. Since no background check or registration is required at the time of purchase (before completion), it offers a level of anonymity not found with traditional firearms transactions.
Disadvantages and Considerations
While there are many advantages to building firearms from 80% lowers, there are also a few potential downsides and considerations.
1. Time and Effort:
Completing an 80% lower requires time, effort, and skill. If you’re not experienced with tools and machining, the process may be more challenging than expected. Additionally, you need to invest time into learning how to properly assemble the firearm.
2. Tooling Costs:
The tools required to complete an 80% lower, such as a milling machine or drill press, can be expensive. For some, these costs may outweigh the savings of building a firearm from scratch, especially if you’re only building one or two firearms.
3. Legal Risk:
In certain states and jurisdictions, laws regarding 80% lowers and ghost guns are constantly evolving. It’s crucial to stay informed about any changes in the law, as failing to comply with regulations can result in serious legal consequences.
Conclusion
80% lowers are an exciting and accessible way for firearm enthusiasts to build custom guns while saving money and gaining hands-on experience. While the process of completing and assembling a firearm from an 80% lower can be challenging, the benefits—such as full customization, the satisfaction of building your own firearm, and privacy—make it worthwhile for many people.
However, it’s essential to be aware of the legal landscape surrounding 80% lowers. Before starting your build, make sure you are familiar with both federal and state laws, as they can vary and change over time. Whether you’re a seasoned gun builder or a beginner looking to learn more, 80% lowers provide a unique opportunity to create a firearm tailored to your preferences.
