Building your own AR-15 can be a rewarding experience, allowing for customization and a deep understanding of your firearm. Many builders opt to purchase an AR-15 kit containing all the necessary components except the lower receiver, as this is the serialized part requiring registration. This guide will walk you through what to expect in a complete upper and lower parts kit, considerations for choosing your components, and what you'll need beyond the kit itself.
Understanding the AR-15 Lower Receiver
Before diving into the kit, it's crucial to understand the significance of the lower receiver. It's the heart of the firearm, housing the trigger group, fire control components, and buffer tube. Legally, it's considered the firearm itself, requiring registration and background checks. Purchasing a complete lower receiver separately ensures compliance with all relevant laws and regulations.
What's Included in a Typical AR-15 Kit (Excluding Lower)?
A comprehensive AR-15 kit, excluding the lower receiver, typically includes:
Upper Receiver Group:
- Upper Receiver: The top portion of the firearm, where the barrel and bolt carrier group are housed.
- Barrel: The barrel length significantly impacts the rifle's performance. Common lengths range from 10.5" to 20", each offering different advantages in terms of accuracy, velocity, and maneuverability. Choose based on your intended use.
- Gas System: This system regulates the gas pressure to cycle the action. Common options include direct impingement and piston-driven systems.
- Bolt Carrier Group (BCG): This moves the bolt back and forth, cycling the action. High-quality BCGs are essential for reliability.
- Charging Handle: Used to manually cycle the bolt.
- Handguard/Rail System: Protects the barrel and provides mounting points for accessories. Lengths and materials vary.
- Gas Tube: Connects the gas block to the upper receiver.
- Front and Rear Sights (Optional): Many kits offer the option of including iron sights. These are often replaceable with more advanced optic systems.
Other Components:
- Buffer Tube: Houses the buffer spring and buffer.
- Buffer Spring: Provides recoil mitigation.
- Buffer: Reduces recoil further.
- Pistol Grip: Provides a comfortable grip.
- Upper Receiver Parts: These are often smaller parts needed to complete the upper.
Choosing Your AR-15 Kit Components: Key Considerations
The quality of your components will directly impact the performance and reliability of your AR-15. When choosing a kit, consider:
- Barrel Material: Common options include chrome-moly vanadium steel (CMV) and stainless steel. CMV offers a balance of strength and cost-effectiveness, while stainless steel provides superior corrosion resistance.
- Gas System Type: Direct impingement is simpler and generally less expensive, while piston systems are known for reducing fouling.
- BCG Material: Look for a BCG made from high-quality materials like Carpenter 158 steel for enhanced durability.
- Manufacturer Reputation: Research the manufacturer's reputation for quality and customer service.
Beyond the Kit: What Else You'll Need
Even with a complete kit, you'll need a few additional items:
- Lower Receiver: As mentioned previously, this is the serialized part that requires registration and a background check.
- Tools: You'll need various tools for assembly, including a torque wrench for proper tightening of components.
- Ammunition: You'll need ammunition that matches your chosen caliber.
- Optics (Optional): Consider adding a red dot sight, holographic sight, or scope for improved accuracy and target acquisition.
Conclusion
Building your own AR-15 from a kit is a fulfilling project that allows for extensive customization. By carefully selecting your components and understanding the process, you can create a reliable and accurate firearm tailored to your specific needs. Remember to always comply with all federal, state, and local laws and regulations when building and owning firearms.
