For firearm enthusiasts who enjoy the challenge of creating something from scratch, working with 80% lowers offers a rewarding experience. These partially completed lower receivers are an excellent starting point for building custom firearms. Whether you’re looking to save on costs, gain new skills, or craft a unique weapon, understanding how to work with 80% lowers is essential for any DIY firearm builder. Here’s everything you need to know about 80% lowers, including the benefits, the legalities, and how to complete the build yourself.
What Is an 80% Lower and How Does It Work?
An 80% lower is an unfinished lower receiver that’s been partially machined, leaving only 20% of the work to be done before it can be used in a fully operational firearm. These lowers are popular because they are legally not considered firearms until completed, allowing you to buy them without requiring a background check or FFL.
To turn the 80% lower into a functioning firearm component, you need to finish the machining process. This often involves drilling the necessary holes, milling out the trigger pocket, and refining other critical parts to fit the rest of the firearm. The result is a custom lower receiver that fits your exact specifications.
Why Choose an 80% Lower?
1. Cost Savings: Purchasing a fully completed lower receiver can be expensive, especially for high-quality parts. Opting for an 80% lower allows you to save money by doing the work yourself, which can be particularly appealing for those on a budget or looking to get more value out of their builds.
2. Customization and Personalization: One of the biggest draws of building your own firearm is the ability to fully customize it. From choosing parts that fit your shooting style to experimenting with different finishes and designs, an 80% lower offers a great deal of creative freedom. Whether you want a different grip or a custom trigger mechanism, you control every detail.
3. Building Skills: The process of machining and assembling an 80% lower offers a hands-on learning experience. If you’re new to gunsmithing or want to improve your skills, completing an 80% lower is a great way to deepen your understanding of firearms and their mechanics. It’s also an opportunity to learn about machining tools and how to work with metal.
4. Privacy and Independence: Another reason some gun owners choose to build their own firearm is the sense of privacy it offers. Because 80% lowers are not classified as firearms, they can be purchased without registration or background checks. Once completed, you have a personal firearm that doesn’t require federal tracking.
Navigating the Legal Landscape
Though building with an 80% lower is legal, it’s important to understand the associated laws. Here’s a breakdown of the legal requirements and restrictions:
- State Laws Matter: While the federal government permits the purchase of 80% lowers, some states have stricter regulations. For example, California has passed laws that require a serial number to be added to 80% lowers before completion. Other states may prohibit the possession or sale of unfinished lowers, so always check your local laws before purchasing.
- Completion Turns It Into a Firearm: Once you finish machining your 80% lower and assemble it into a fully functional firearm, it is considered a firearm under the law. This means you must follow the same legal requirements as for any other gun, including adding a serial number (depending on your location) and adhering to state regulations regarding gun ownership and transfers.
- Selling or Transferring Your Build: If you decide to sell or transfer your completed firearm, be sure to follow the correct legal processes. Many states require background checks for private sales or transfers, so ensure that you’re complying with all applicable laws.
How to Finish Your 80% Lower: The DIY Process
Building a firearm from an 80% lower requires both the right tools and patience. Here’s how you can complete the lower receiver and assemble your firearm:
1. Basic Tools Required: The simplest approach involves using hand tools like a drill press, jigs, and a set of basic gunsmithing tools. However, for more precision and efficiency, many builders opt for a CNC (Computer Numerical Control) machine, which automates much of the cutting and milling work.
2. Jigs and Kits: Many builders purchase 80% lower kits, which come with a jig that guides you through the machining process. These kits include all the necessary tools to finish the lower, including drills, bits, and even templates. The jig ensures that cuts are made accurately, reducing the likelihood of mistakes.
3. The Machining Process: The most critical part of finishing an 80% lower is milling the fire control pocket and drilling holes for the pins that will hold the trigger group. These steps require precise measurements and careful attention to detail. Most builders will use a combination of drilling and milling to complete the necessary cuts.
4. Tools and Techniques for the Experienced Builder: If you’re more experienced or have access to specialized equipment, you can use advanced tools like a mill or CNC machine. These machines can make the process quicker and more precise, but they require a high level of expertise to use safely.
Safety and Testing Your Firearm
After completing your firearm, it’s essential to ensure it functions correctly and safely. Here are a few important steps:
- Function Testing: Before using your firearm, conduct thorough function checks to ensure all components work properly. Test the trigger mechanism, the magazine release, and other parts to make sure everything operates smoothly.
- Inspection: It’s a good idea to have a professional inspect your firearm, especially if you’re new to building. A gunsmith can look over your completed firearm to ensure that all parts are fitted correctly and that it’s safe to fire.
- Safe Handling: As with any firearm, always use safety equipment like ear protection and safety glasses when testing your weapon. Always test your build in a safe, controlled environment, such as a shooting range.
The Pros and Cons of 80% Lowers
Like any firearm-building project, working with 80% lowers comes with both advantages and challenges. Here are the main pros and cons:
Pros:
- Lower cost compared to fully assembled lowers.
- Full control over customization and design.
- Privacy and no background check required for the 80% lower.
- A rewarding learning experience.
Cons:
- Requires time, tools, and skill to finish the lower.
- Legal complexities, particularly with state laws.
- The process can be frustrating for beginners without access to professional-grade equipment.
Final Thoughts: Is an 80% Lower Right for You?
Building your own firearm using an 80% lower receiver is a highly customizable and educational process. It can save money, offer a sense of accomplishment, and allow you to create a firearm tailored to your needs. However, it’s important to be prepared for the legal and technical aspects of the build. If you’re ready for the challenge and have the necessary tools, completing an 80% lower can be a deeply rewarding experience.
To begin your next project, visit 80-Lower.com for a wide selection of 80% lowers and tools to help you get started.