Building your own AR-15 can be a rewarding experience, offering a level of customization unavailable with pre-assembled rifles. This guide focuses on AR-15 kits that exclude the lower receiver, the serialized part of the firearm that's subject to stricter regulations. Understanding what's included, the legality, and the assembly process will help you navigate the world of AR-15 builds.
What's Included in an AR-15 Kit (No Lower)?
An AR-15 kit, excluding the lower receiver, typically contains all the parts necessary to assemble a complete upper receiver group. This usually includes:
- Upper Receiver: The topmost part of the rifle, housing the bolt carrier group and barrel.
- Barrel: The heart of the firearm, determining accuracy and caliber. Barrel length significantly impacts performance. Common lengths include 16 inches (standard), 14.5 inches (often with a pinned flash hider to reach 16 inches), and shorter lengths for more compact builds. Consider the intended use; shorter barrels are more maneuverable but often have increased recoil.
- Bolt Carrier Group (BCG): This is the moving part that cycles the ammunition. Quality BCGs are crucial for reliability. Consider the material (e.g., Carpenter 158 steel, nickel boron coated) and manufacturer reputation.
- Charging Handle: Used to manually cycle the BCG, loading a round into the chamber. Ambidextrous charging handles are a popular upgrade.
- Gas Tube: Connects the gas block to the bolt carrier group, transferring gas pressure from the barrel to cycle the action.
- Gas Block: Regulates the amount of gas that enters the gas tube. Low-profile gas blocks are common choices.
- Handguard/Rail System: Protects the barrel and provides mounting points for accessories like lights and optics. Various lengths and designs are available, including M-LOK and KeyMod systems.
- Muzzle Device (Often): This can be a flash hider, compensator, or suppressor. Regulations on muzzle devices vary by location. Note that some kits may not include this.
- Sights (Sometimes): Iron sights, including front and rear sights, may be included depending on the kit. Many builders prefer to add optics.
Legal Considerations: The Importance of the Lower Receiver
It's crucial to understand the legal aspects of owning and building AR-15s. The lower receiver is the regulated component of the firearm, containing the serial number and considered the firearm itself by the Bureau of Alcohol, Tobacco, Firearms and Explosives (ATF). Building your own AR-15 requires obtaining a lower receiver legally, either through purchase from a licensed dealer or through the completion of a compliant 80% lower receiver build. Failure to comply with all applicable federal, state, and local laws regarding firearms is a serious offense. Always check your local and state regulations before purchasing any parts.
80% Lower Receivers: A Note of Caution
80% lower receivers are unfinished receivers that require significant machining before they can be used. While they avoid some regulations in certain jurisdictions, completing them still requires compliance with all applicable laws. Incorrectly completing an 80% lower receiver could lead to legal trouble.
Assembling Your AR-15 Kit: A Step-by-Step Overview
Assembling an AR-15 is a relatively straightforward process, but it requires attention to detail and the proper tools. Numerous online resources provide detailed visual guides, but here’s a simplified overview:
- Install the Barrel Nut: This secures the barrel to the upper receiver.
- Attach the Handguard: This is usually attached with screws or a clamp system.
- Install the Gas Tube: Connect the gas tube between the gas block and the bolt carrier group.
- Assemble the Bolt Carrier Group: Ensure the bolt and carrier are correctly aligned.
- Install the Charging Handle: Insert the charging handle into the upper receiver.
- Mount the Upper Receiver: Align the upper receiver with the lower receiver and attach it.
- Attach the Muzzle Device (if applicable): Use the appropriate tools to attach the muzzle device.
Choosing the Right Kit: Factors to Consider
Several factors influence the selection of an AR-15 kit:
- Budget: Prices range significantly depending on the quality of components.
- Intended Use: A kit for target shooting will differ from one intended for home defense.
- Caliber: .223/5.56mm is the most common, but other calibers like .300 Blackout are available.
- Barrel Length: Shorter barrels provide increased maneuverability, while longer barrels enhance accuracy.
- Brand Reputation: Choosing reputable manufacturers ensures quality and reliability.
Conclusion: Building Your Custom AR-15
Building your own AR-15 from a kit (excluding the lower) allows for a high degree of customization and a deeper understanding of the firearm. However, it's essential to prioritize safety and legal compliance. Thorough research, careful assembly, and adherence to all relevant laws are critical throughout the entire process. Remember to always consult with local and state authorities to ensure your actions are legal and safe.