Building a 20-inch AR-15 is a unique undertaking, deviating from the standard configurations often seen. While the shorter barrel lengths are popular for maneuverability and close-quarters combat, a 20-inch barrel offers distinct advantages for accuracy and long-range shooting. This guide explores the considerations, components, and potential applications of a 20-inch AR build.
Why Choose a 20-Inch AR Barrel?
The primary benefit of a 20-inch barrel is improved ballistic performance. The longer barrel allows for more complete powder burn, resulting in higher muzzle velocity and increased accuracy. This translates to flatter trajectories and less bullet drop at longer ranges, making it ideal for precision shooting, hunting, or competitive shooting disciplines demanding accuracy at distance. However, increased barrel length compromises maneuverability; therefore, this build isn't ideal for close-quarters combat or situations requiring quick target acquisition in tight spaces.
Key Components of a 20-Inch AR Build
Building any AR-15 requires careful selection of high-quality components. For a 20-inch build, these choices are even more critical to maximize the potential of the longer barrel.
1. Barrel: The Foundation of Accuracy
The barrel is arguably the most important part of your build. A 20-inch barrel typically utilizes a heavier profile, like a mid-length or heavy profile, to enhance stability and dissipate heat effectively during extended firing sessions. Consider chrome-lined barrels for increased durability and easier cleaning. The choice of barrel material (e.g., 4150 chrome moly vanadium steel, stainless steel) also affects accuracy, weight, and cost. Look for reputable manufacturers known for producing high-precision barrels.
2. Upper Receiver: The Housing for Precision
A quality upper receiver ensures proper barrel alignment and a secure fit for all components. Choose a forged upper receiver for its strength and durability. Ensure compatibility with your chosen barrel's gas system (direct impingement or piston).
3. Lower Receiver: The Control Center
The lower receiver houses the fire control group and the buffer tube assembly. While many lower receivers are similar, some offer enhanced ergonomics or features. Choose a reliable lower receiver from a reputable manufacturer.
4. Gas System: Optimizing Performance
A 20-inch barrel will likely use a mid-length or rifle-length gas system. Mid-length systems offer a balance between reliability and reduced recoil. Rifle-length systems are known for their reliability but can produce more felt recoil. The gas system's length significantly influences the functionality of your AR-15.
5. Handguard: Protecting and Stabilizing
The handguard protects the barrel and provides a mounting point for accessories like optics and lights. A free-floating handguard minimizes barrel contact, contributing to improved accuracy.
6. Stock and Grip: Enhancing Ergonomics
The stock and grip directly influence comfort and shooting stability. Select a stock and grip that fit your hand size and shooting style. Adjustable stocks allow for customization based on individual preferences.
7. Trigger: Refining the Shooting Experience
A quality trigger is crucial for accurate and consistent shooting. Consider upgrading to a match-grade trigger for improved performance.
8. Optics: Enhancing Accuracy and Target Acquisition
The choice of optic depends on your intended use. For long-range shooting, a scope with sufficient magnification is necessary. For closer ranges, a red dot sight might be more suitable.
Building Your 20-Inch AR: Step-by-Step
Building an AR-15 involves assembling the components carefully and securely. Numerous resources are available online, including detailed video tutorials, which can guide you through the process. Safety should be your utmost priority during the assembly process. If you're uncertain about any step, it's always advisable to seek the assistance of an experienced gunsmith.
Legal Considerations
Before building any firearm, ensure that you comply with all applicable federal, state, and local laws and regulations.
Conclusion: The Power of Precision
A 20-inch AR build offers a unique platform for long-range accuracy and precision shooting. By selecting high-quality components and following proper assembly procedures, you can create a highly effective and reliable firearm. Remember to prioritize safety and legal compliance throughout the entire process. This guide serves as a starting point for your research; further exploration into specific component choices will enhance your understanding and aid in building your ideal 20-inch AR-15.
