Building your own AR-10 from an 80% lower receiver can be a rewarding experience, offering customization and potential cost savings. However, it's crucial to understand the legal implications and technical aspects before embarking on this project. This guide provides a comprehensive overview of AR-10 80% lower receivers, covering everything from legal considerations to assembly and customization.
Understanding AR-10 80% Lower Receivers
An AR-10 80% lower receiver is an unfinished firearm receiver that lacks the critical components required to be considered a complete firearm. The "80%" refers to the percentage of machining or manufacturing that remains to be completed before it becomes a functional firearm lower receiver. Crucially, this unfinished state places it outside the scope of certain federal regulations, depending on your location. This is a key distinction and why they're popular with builders.
Legal Considerations: Navigating the Complexities of 80% Receivers
The legal landscape surrounding 80% lowers is complex and varies significantly by state and even local jurisdiction. Federal law generally does not regulate 80% lowers, as they are not considered firearms until they are completed. However, many states have enacted their own laws restricting or prohibiting the possession or manufacture of these components. It is absolutely imperative to research your local and state laws before purchasing or working with any 80% lower receiver. Failure to do so can result in serious legal penalties.
- State-Specific Regulations: Some states require registration, licensing, or background checks for even unfinished receivers. Others may completely ban their possession or sale.
- Federal Laws: While federal laws generally don't regulate 80% lowers directly, they do regulate the completed firearm. Improper assembly or subsequent modification can lead to violations.
Building Your AR-10 from an 80% Lower: A Step-by-Step Guide
The process of completing an AR-10 80% lower receiver requires specific tools and skills. Improper completion can result in a malfunctioning or unsafe firearm.
Tools and Materials Required
The necessary tools and materials will vary depending on the specific 80% lower receiver and your chosen method of completion (jig vs. milling machine). Generally, you'll need:
- 80% AR-10 Lower Receiver: Choose a reputable manufacturer known for quality and precision.
- Jigs or Milling Machine: Jigs provide a guided process for less experienced builders. A milling machine offers greater precision and control.
- Appropriate Drill Bits and End Mills: Precision is vital for proper functionality.
- Safety Glasses and Hearing Protection: Always prioritize safety when working with power tools.
- Firearm Assembly Tools: These will be needed to complete the build after milling.
- Upper and Lower Receiver Parts Kit: This kit contains all necessary internal parts to complete the rifle.
Note: Never attempt to complete an 80% lower receiver without the proper tools, knowledge, and safety precautions.
Step-by-Step Assembly (using a jig as an example):
- Secure the 80% lower in the jig. Follow the manufacturer's instructions carefully.
- Drill the necessary holes. Use slow speeds and multiple passes to prevent overheating and damage.
- Mill the necessary surfaces. Again, follow the manufacturer's instructions for proper depth and positioning.
- Remove the completed lower from the jig. Inspect it carefully for any imperfections.
- Assemble the lower receiver. Install the trigger group, hammer, safety selector, and other components.
- Assemble the complete firearm. Install the upper receiver and other necessary components.
Customization Options for Your AR-10
One of the main advantages of building your own AR-10 from an 80% lower is the extensive customization options available. You can personalize your build to suit your needs and preferences.
Choosing the Right Parts
Numerous manufacturers offer a vast array of parts for AR-10s, allowing for customization of:
- Stocks: Choose from fixed, adjustable, or collapsible stocks for personalized ergonomics.
- Handguards: Select a handguard material (aluminum, polymer, wood) and style (M-LOK, KeyMod) to match your preferences.
- Triggers: Enhance trigger pull with aftermarket triggers for improved accuracy and performance.
- Barrels: Different barrel lengths and profiles affect accuracy and performance.
Case Study: Comparing Build Costs
Building an AR-10 from an 80% lower receiver can result in significant cost savings compared to purchasing a complete rifle. The exact savings depend on the cost of the 80% lower, parts, tools, and jig. A rough comparison might look like this:
| Item | Cost from 80% build | Cost from Pre-Built rifle |
|---|---|---|
| 80% Lower Receiver | $100 - $200 | Included in pre-built cost |
| Parts Kit | $300 - $500 | Included in pre-built cost |
| Tools & Jig | $100 - $300 | N/A |
| Total Estimated Cost | $500 - $1000 | $1000 - $2000 |
Disclaimer: These costs are estimates and may vary significantly based on chosen components and retailer.
Conclusion: Responsible AR-10 Building
Building an AR-10 from an 80% lower receiver can be a satisfying project, offering significant customization potential and potential cost savings. However, it's crucial to prioritize safety, legal compliance, and responsible gun ownership. Thoroughly research your local and state laws, ensure proper tooling and expertise, and always handle firearms safely. Remember that building a firearm is a serious undertaking with significant responsibility.