Building your own AR-15 can be a rewarding experience, offering customization and a deep understanding of your firearm. This guide focuses on the components you'll need for your AR-15 build, excluding the lower receiver (which requires separate legal considerations and processes). We'll cover the essential parts, providing insights into their function and variations available.
Understanding the AR-15 Upper Receiver Group
The upper receiver group is the heart of the AR-15's functionality, housing the barrel, bolt carrier group, and charging handle. Let's break down the key components:
1. Upper Receiver: The Foundation
The upper receiver is the main chassis of the upper assembly. It's a sturdy piece of aluminum that houses the bolt carrier group, the barrel, and the forward assist. You'll find variations in material (e.g., forged, billet), finish (e.g., anodized, Cerakote), and features (e.g., forward assist, dust cover). Choose an upper receiver that aligns with your budget and desired aesthetics.
2. Barrel: Accuracy and Performance
The barrel is where the magic happens – the projectile is propelled down the barrel, gaining speed and accuracy. Barrel length significantly impacts performance, with longer barrels generally offering greater velocity and accuracy. Consider the intended use of your AR-15 when selecting a barrel length (e.g., shorter barrels for close-quarters combat, longer barrels for precision shooting). Material (e.g., chrome-lined, stainless steel) and profile (e.g., government profile, lightweight profile) also affect accuracy and weight.
3. Bolt Carrier Group (BCG): The Engine
The BCG is the mechanism that cycles the ammunition and ejects spent casings. It’s a complex assembly containing several critical parts, including the bolt, carrier, firing pin, and extractor. High-quality BCGs are crucial for reliable operation. Choose a BCG from a reputable manufacturer, ensuring proper tolerances and materials for longevity and dependable function. Variations include nickel boron-coated BCGs for smoother operation and reduced friction.
4. Charging Handle: Manipulating the System
The charging handle is used to manually cycle the BCG. Different charging handles offer variations in size, shape, and ambidextrous features, affecting ease of use. Selecting a charging handle that fits your hand size and shooting style enhances efficiency and comfort.
5. Gas System: Regulating Pressure
The gas system, comprising the gas tube and gas block, regulates the gas pressure that drives the BCG. Different gas systems (e.g., direct impingement, piston-driven) offer varying levels of reliability, cleanliness, and recoil. Understanding the pros and cons of each system is crucial for selecting the right option for your build.
6. Handguard/Rail System: Accessories and Stability
The handguard protects your hand from the hot barrel and provides mounting points for accessories like optics, lights, and vertical grips. Various handguards are available, from free-floating rails to simpler drop-in handguards. Consider the accessories you plan to use and choose a handguard with sufficient mounting points and ergonomics.
Beyond the Upper: Other Essential Components
While the upper receiver group forms the core shooting mechanism, several other components are crucial for a complete build:
- Buttstock: Provides a stable and comfortable shoulder rest. Several variations exist, from fixed stocks to adjustable stocks, each offering unique benefits.
- Buffer Tube: Houses the buffer spring and buffer, which manage recoil.
- Buffer Spring and Buffer: These work together to control recoil and ensure smooth cycling of the action.
- Pistol Grip: Provides a comfortable grip for the shooter. Ergonomics and material are key factors in choosing a pistol grip.
- Upper Receiver Parts Kit: Includes smaller components like the forward assist, ejector, and pins that are essential for the upper's assembly and function.
Building Your AR-15: A Step-by-Step Approach (Upper Only)
Once you have all the necessary parts, assembling your AR-15 upper receiver group is a relatively straightforward process, though it does require care and attention to detail. Many excellent video tutorials are available online to guide you through this process. Always prioritize safety and follow proper procedures.
Disclaimer: This article is for informational purposes only. Always comply with all applicable federal, state, and local laws and regulations regarding firearm ownership and construction. Improper assembly or modification of firearms can be dangerous.
This guide provides a comprehensive overview of the parts needed to build an AR-15 upper receiver group. Remember to research thoroughly and choose components from reputable manufacturers to ensure the safety and reliability of your build. Always prioritize safety and handle firearms responsibly.
