80 Lower Receiver Aluminum: Top 3 Best Choices in 2024

Why 80% Lower Receiver Aluminum Matters

Building your own AR-15 can be an exciting, educational, and rewarding experience. At the heart of every custom build is the 80% lower receiver aluminum, a partially-finished component that allows you to take control of your firearm from start to finish.

Quick Overview:
– 7075-T6 Aluminum: Known for its exceptional strength and hardness.
– 6061-T6 Aluminum: More affordable and easier to machine at home.
– Forged vs. Billet: Forged is mil-spec compatible; billet offers design flexibility.

When you choose to build with an 80% lower, you not only gain a deeper understanding of your firearm but also have the freedom to customize every part to your exact specifications. Completing an 80% lower at home gives you confidence in compatibility and performance, ensuring a truly custom firearm build that meets your needs.

However, choosing the right 80% lower receiver involves understanding the materials, specifically the kinds of aluminum used—7075-T6 and 6061-T6. Both have their own benefits, making your selection process crucial for a successful build.

Understanding 80% Lower Receivers

What is an 80 Lower Receiver Aluminum?

An 80 lower receiver aluminum is an unfinished, unserialized receiver that’s 80% complete. It requires additional machining to become a fully functional firearm part. The ATF (Bureau of Alcohol, Tobacco, Firearms and Explosives) does not classify these as firearms, so they don’t need a serial number or background check to purchase.

Materials: These receivers are typically made from high-quality aluminum. The two most common grades are 7075-T6 and 6061-T6.

• 7075-T6 Aluminum: Known for its high tensile strength and durability. This makes it ideal for AR builds where strength is crucial.
• 6061-T6 Aluminum: Easier to machine and more cost-effective, making it popular among DIY enthusiasts.

Benefits: Using aluminum offers several advantages:
– Durability: Both grades provide excellent strength and longevity.
– Lightweight: Aluminum keeps the firearm lightweight.
– Corrosion Resistance: Anodized finishes add extra corrosion resistance.

Legal Considerations for 80% Lowers

Serialization: While 80% lowers do not require serialization under federal law, some states have specific requirements. For example, California and New York mandate serialization once the lower is completed.

State Laws: Local and state laws vary widely. Some states, like New Jersey and Washington, have banned 80% lowers altogether. Always check your local regulations before purchasing.

ATF Definition: The ATF officially classifies an 80% lower as a “receiver blank.” Since it’s not fully machined, it isn’t considered a firearm. This is why you can buy one without going through an FFL (Federal Firearms License) dealer.

Legal Status: However, once you finish machining the lower, it becomes a firearm and must comply with all federal and state laws. Selling a completed lower without being a licensed manufacturer can lead to serious legal consequences.

Note: Always ensure you’re sourcing your 80% lower from reputable retailers who provide clear information about the legality and regulations in your state.

By understanding what an 80 lower receiver aluminum is and the legal landscape surrounding it, you can make informed decisions and enjoy a successful DIY firearm build.

Types of Aluminum Used in 80% Lowers

When it comes to 80 lower receiver aluminum, two types are most commonly used: 7075-T6 and 6061-T6. Both offer unique benefits, but it’s important to know their differences to make the best choice for your AR build.

Benefits of 7075-T6 Aluminum in AR Builds

7075-T6 aluminum is known for its exceptional strength and durability. This makes it a top choice for those looking to build a high-performance AR.

• Durability: 7075-T6 is harder and more resilient than most other aluminum alloys. It can withstand significant stress, making it ideal for rigorous use.

• Tensile Strength: This type of aluminum boasts a tensile strength of around 83,000 psi, which is significantly higher than 6061-T6. This ensures that your AR can handle high-pressure situations without deformation.

• Usage: Given its strength and durability, 7075-T6 is often used in military applications. If you want your AR to meet or exceed mil-spec standards, 7075-T6 is the way to go.

Advantages of 6061-T6 Aluminum for DIY Enthusiasts

6061-T6 aluminum is also a popular choice, especially among DIY builders. It offers several advantages that make it an attractive option.

• Machinability: One of the biggest benefits of 6061-T6 aluminum is its ease of machining. It’s softer than 7075-T6, which makes drilling and milling much simpler for those working at home.

• Cost-Effectiveness: 6061-T6 is generally less expensive than 7075-T6. This makes it a more budget-friendly option, especially for beginners who are just getting into DIY firearm building.

• Popularity: Due to its balance of strength and machinability, 6061-T6 is widely used in various applications, from automotive parts to aerospace components. It’s a versatile material that meets the needs of many DIY builders.

Comparison Table: 7075-T6 vs. 6061-T6 Aluminum

Feature	7075-T6 Aluminum	6061-T6 Aluminum
Tensile Strength	~83,000 psi	~45,000 psi
Machinability	Moderate	High
Cost	Higher	Lower
Durability	Very High	High
Common Usage	Military, High-stress applications	DIY, General-purpose

Choosing between 7075-T6 and 6061-T6 aluminum depends on your specific needs and experience level. If you prioritize strength and durability, go with 7075-T6. If ease of machining and cost are more important, 6061-T6 is your best bet.

In the next section, we’ll discuss how to choose the right 80% lower receiver for your build.

How to Choose the Right 80% Lower Receiver

Choosing the right 80% lower receiver aluminum for your AR build can be overwhelming. Here’s how to make the best choice.

Factors to Consider When Selecting an 80% Lower

Compatibility: Ensure the lower you choose is compatible with the parts you plan to use. Mil-spec lowers are a safe bet for compatibility with most AR-15 parts.

Customization: Think about how much you want to customize your firearm. Billet lowers often allow for more unique designs and features, like flared magwells or ambidextrous controls.

Cost: Your budget will play a big role. Forged lowers are usually less expensive than billet lowers, but both types offer high quality.

Material: Both 7075-T6 and 6061-T6 aluminum are great choices. 7075-T6 is stronger and more durable, while 6061-T6 is easier to machine and often cheaper.

Finish: Anodized finishes provide extra corrosion resistance. If you plan to engrave or customize the finish, non-anodized lowers might be better.

Mil-spec Standards: If you want your build to meet military specifications, go with a forged, mil-spec lower. These are made to strict standards and will fit most AR-15 parts.

Comparing Billet and Forged 80% Lowers

Strength: Forged lowers are generally stronger due to the forging process that aligns the metal’s grain structure. Billet lowers are also strong but may not reach the same level of durability.

Weight: Forged lowers are often lighter because they use less material. Billet lowers can be heavier, depending on the design.

Aesthetic Differences: Billet lowers are usually chosen for their unique looks and customization options. Forged lowers have a more traditional appearance.

Practical Example: If you want a rifle that looks unique and customized, a billet lower might be the way to go. If you need a reliable, cost-effective option that meets mil-spec standards, go for a forged lower.

These factors will help you pick the perfect 80% lower receiver for your AR build. Next, we’ll dive into the steps and tools needed to complete your lower receiver.

Completing Your 80% Lower Receiver

Step-by-Step Guide to Milling an 80% Lower

Completing an 80% lower receiver can be a rewarding DIY project. Here’s a step-by-step guide to help you through the process:

1. Preparation:

• Read Instructions: Start by thoroughly reading the manufacturer’s instructions. Each 80% lower might have slight variations.
• Gather Tools: Ensure you have all the necessary tools (listed below) ready and organized.

2. Secure the Lower Receiver:

• Vise and Clamps: Use a vise and clamps to securely mount the 80% lower receiver. This ensures it doesn’t move during milling.

3. Remove Excess Material:

• Milling Machine or Drill Press: Use a milling machine or drill press to remove the specified areas of material. Follow the guidelines provided by the manufacturer.
• Precision: Take your time to ensure precision. Use calipers and rulers to double-check measurements.

4. Drill Necessary Holes:

• Drill Bits and End Mills: Drill holes for the trigger assembly, safety selector, and other necessary components.

5. Finish the Trigger Pocket:

• Finishing End Mill: Use a finishing end mill to clean up the trigger pocket and other areas that require additional machining.

6. Clean and Inspect:

• Thorough Cleaning: Once milling is complete, thoroughly clean the lower receiver to remove any metal shavings.
• Inspection: Inspect the receiver for any imperfections or areas that may need additional work.

Essential Tools for Finishing an 80% Lower

To complete your 80% lower receiver, you’ll need a few essential tools:

1. Milling Machine or Drill Press:** Crucial for removing excess material.

2. Drill Bits and End Mills:** Used to drill holes and finish the milling process.

3. Vise and Clamps:** These will hold your lower receiver securely in place.

4. Safety Equipment:**

• Safety Glasses: Protect your eyes from metal shavings.
• Gloves: Keep your hands safe from sharp edges.

5. Measuring Tools:**

• Calipers and Rulers: Ensure precision in your measurements.

6. Jig:**

• Jig: A jig makes the milling process more convenient and accurate. It guides your drilling and milling, ensuring precision and reducing the chance of errors.

7. Cutting Fluid:** Helps to keep the tools and material cool, reducing wear and tear on the equipment.

8. Shop Vac:** Useful for cleaning up metal shavings and keeping your workspace tidy.

Pro Tip: Always prioritize safety when working with tools. Wear safety glasses and gloves, and take your time to ensure each step is done correctly.

By following these steps and using the right tools, you’ll be well on your way to completing your 80% lower receiver. Ready to start your build? Let’s move on to the best practices for purchasing your 80% lower.

Frequently Asked Questions about 80 Lower Receiver Aluminum

What aluminum is used for AR lowers?

AR lowers are commonly made from two types of aluminum: 6061-T6 and 7075-T6.

• 6061-T6 Aluminum: Easier to machine, making it a popular choice for DIY enthusiasts. It’s more than strong enough for typical use and is often favored for home builds due to its machinability.

• 7075-T6 Aluminum: Known for its superior strength and hardness. This type of aluminum is typically used in military-spec (mil-spec) firearms. While it is tougher to machine, it offers increased durability and tensile strength.

Both types are excellent choices, but your specific needs and skill level will determine which is best for you.

Do 80 percent lowers need to be serialized?

No, 80 percent lowers do not require serialization under federal law because they are not considered complete firearms. However, once you complete the machining process, some states do require serialization for personal use firearms.

States with serialization requirements include:

• California
• Connecticut
• New York
• New Jersey
• Maryland
• Hawaii

Always check your local laws to ensure compliance.

What’s better, billet or forged lowers for AR?

Both billet and forged lowers have their own advantages and can be suitable depending on your needs.

• Forged Lowers: These are made by heating and hammering aluminum into shape, resulting in a denser and often stronger product. They are mil-spec compatible and generally considered more durable.

• Billet Lowers: These are CNC machined from a solid block of aluminum, allowing for more intricate designs and customization options. While they may not always be mil-spec compatible, they offer unique aesthetic and functional features.

Key Differences:

Feature	Forged Lowers	Billet Lowers
Strength	Higher due to forging process	High, but slightly less than forged
Compatibility	Mil-spec	May not be mil-spec
Customization	Limited	High, allows for unique designs
Machinability	Tougher to machine	Easier to machine

The choice between billet and forged lowers comes down to your specific requirements for strength, compatibility, and customization.

Now that we’ve covered the most frequently asked questions, let’s dive into the best practices for purchasing your 80% lower.

Conclusion

When it comes to choosing the best aluminum 80% lower receiver for your AR build, Daytona Tactical provides top-quality options you can trust. Our selection includes both 7075-T6 and 6061-T6 aluminum lowers, ensuring you find the right fit for your DIY firearm project.

At Daytona Tactical, we’re committed to offering superior products and exceptional customer support. Our team is always ready to answer your questions and guide you through the selection process. Whether you’re a seasoned builder or new to DIY firearms, we have the resources and expertise to help you succeed.

Why Choose Daytona Tactical?

1. High-Quality Products: Our 80% lower receivers are crafted with precision and care, ensuring durability and reliability.
2. Customer Support: We stand by our products and are here to assist you with any questions or concerns.
3. Wide Selection: From billet to forged, anodized to non-anodized, we offer a variety of options to meet your needs.

Product Availability

Our inventory includes a diverse range of 80% lowers and related components. Whether you need a single lower receiver or a complete build kit, we have you covered. Check out our AR-15 Lower Upper Sets to find the perfect match for your next project.

Execute your right to bear arms today. Your build awaits!