Building your own AR-15 can be a rewarding experience, allowing for customization and a deep understanding of your firearm. This guide focuses on the components included in a complete AR-15 kit, excluding the lower receiver (which requires separate purchase and registration due to legal restrictions). We'll break down each part, highlighting key considerations for building a reliable and accurate rifle.
Understanding the AR-15 Lower Receiver's Importance
Before diving into the kit components, it's crucial to understand why the lower receiver is purchased separately. The lower receiver is considered the "firearm" by the Bureau of Alcohol, Tobacco, Firearms and Explosives (ATF) in the United States. It contains the serial number and is subject to strict regulations regarding purchase, transfer, and registration. Purchasing an upper receiver and other components separately is legal and allows for greater flexibility in building a personalized AR-15.
What's Included in a Typical AR-15 Upper Receiver Kit?
An AR-15 upper receiver kit typically includes all the components necessary to complete the upper portion of your rifle. These components usually include:
1. Upper Receiver:
- Material: Usually made from forged 7075-T6 aluminum, offering durability and strength. Consider the finish (e.g., anodized, hard-coat anodized) for corrosion resistance.
- Features: Look for features like forward assist and dust cover for enhanced reliability and operation.
2. Bolt Carrier Group (BCG):
- Material: Typically made from Carpenter 158 steel or similar high-quality materials for longevity and reliability.
- Finish: Consider finishes like nickel boron or nitride for reduced friction and improved performance. Proper lubrication is essential regardless of finish.
3. Charging Handle:
- Type: Ambidextrous charging handles offer increased versatility. Consider the material and build quality for smoother operation.
4. Barrel:
- Length: Barrel length significantly impacts ballistics and accuracy. Common lengths include 16", 18", and 20". Shorter barrels offer increased maneuverability, while longer barrels generally provide greater accuracy and velocity.
- Twist Rate: The twist rate affects bullet stability. Select a twist rate appropriate for the ammunition you plan to use.
- Profile: Different barrel profiles (e.g., government profile, lightweight profile) affect weight and handling characteristics.
5. Gas System:
- Type: Direct impingement (DI) and piston-driven systems are the two main types. DI systems are simpler and more common, while piston systems offer some potential advantages in terms of cleanliness.
6. Gas Tube:
- Material & Length: Ensures proper gas flow from the barrel to the BCG. Must be compatible with the chosen gas system.
7. Handguard:
- Material: Common materials include aluminum, polymer, and carbon fiber. Consider weight, heat dissipation, and mounting options.
- Length & Style: Various styles and lengths are available, each offering a different feel and ergonomic profile. M-LOK and KeyMod systems are popular for attaching accessories.
8. Muzzle Device:
- Type: A flash hider, compensator, or suppressor (requires legal compliance) reduces recoil, muzzle flash, and/or sound.
9. Sights or Optic Mounts:
- Type: Depending on your preference, consider iron sights, red dot sights, or other optical devices. Ensure compatibility with the handguard and upper receiver.
Considerations Before Purchasing Your Kit
Before buying an AR-15 upper receiver kit, carefully consider the following:
- Budget: Prices vary significantly depending on the quality of components.
- Intended Use: The intended use (e.g., target shooting, home defense, hunting) will impact your choices regarding barrel length, accessories, and other features.
- Compatibility: Ensure all components are compatible with each other and your chosen lower receiver.
This guide provides a comprehensive overview of what to expect when purchasing an AR-15 upper receiver kit. Remember to always prioritize safety and comply with all applicable federal, state, and local laws and regulations. Thorough research and careful consideration will help you build the ideal AR-15 to meet your specific needs and preferences.
