The AR-15 platform's versatility is legendary, and a significant factor in that is the ability to easily swap barrels. Among the popular barrel lengths, the 20-inch barrel stands out for its balance of accuracy, velocity, and effective range. This article delves into the specifics of a 20-inch barrel on an AR-15, exploring its performance characteristics, ideal applications, and considerations for choosing one.
Why Choose a 20-Inch AR-15 Barrel?
A 20-inch barrel offers several key advantages that make it a compelling choice for many shooters:
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Increased Velocity and Energy: The longer barrel allows for more complete propellant burn, resulting in higher muzzle velocity and retained energy downrange. This translates to flatter trajectories and increased effective range compared to shorter barrels. This is particularly noticeable with heavier bullets.
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Improved Accuracy: The longer sight radius inherent in a 20-inch barrel contributes to improved accuracy. The longer the sight radius, the smaller the error introduced by shooter inconsistencies. Furthermore, a longer barrel tends to produce less harmonic vibration, which can negatively affect accuracy.
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Enhanced Range: The combination of higher velocity and better accuracy extends the effective range of the AR-15 significantly. This makes the 20-inch barrel ideal for precision shooting at longer distances, such as target practice at 300 yards or beyond.
Comparing 20-Inch Barrels to Other Lengths
Let's compare the 20-inch barrel to other popular AR-15 barrel lengths:
| Barrel Length (inches) | Velocity (approximate) | Effective Range (approximate) | Pros | Cons |
|---|---|---|---|---|
| 10 | Lower | Shorter | Lightweight, maneuverable | Reduced velocity, accuracy, and range |
| 16 | Moderate | Moderate | Balance of weight, velocity, and range | |
| 20 | Higher | Longer | Excellent accuracy and range | Heavier, less maneuverable |
| 24 | Highest | Longest | Maximum velocity and accuracy | Heaviest, least maneuverable |
(Note: Velocity and effective range are approximate and dependent on ammunition type and other factors.)
Applications for a 20-Inch AR-15 Barrel
The 20-inch barrel is well-suited for a variety of applications:
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Long-Range Shooting: Its superior accuracy and velocity make it ideal for long-range target shooting competitions and hunting.
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Precision Rifle: When built into a precision rifle configuration (with a quality scope and stock), a 20-inch barrel delivers exceptional accuracy at extended ranges.
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Hunting: For hunting larger game at moderate to longer distances, a 20-inch barrel offers the needed stopping power and accuracy. The higher energy transfer is also beneficial.
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Law Enforcement/Military (Select Applications): While shorter barrels are common for close-quarters combat, some specialized law enforcement and military roles utilize longer barrels for precision shooting from greater distances.
Choosing the Right 20-Inch Barrel: Profile and Material
The profile and material of the barrel are crucial considerations:
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Barrel Profile: Different profiles (e.g., mid-length, lightweight, heavy) impact weight, heat dissipation, and stiffness. Heavy barrels offer superior accuracy but are heavier, while lightweight barrels are lighter and more maneuverable but might compromise accuracy slightly at long ranges.
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Barrel Material: Common materials include chrome moly vanadium steel (CMV), stainless steel, and chrome-lined barrels. Stainless steel barrels are known for corrosion resistance, while chrome-lined barrels are durable and easy to clean. CMV is a common and cost-effective choice.
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Gas System: The gas system length (carbine, mid-length, rifle) affects how the gas is channeled to operate the bolt carrier group. Rifle-length gas systems are typically used with 20-inch barrels and offer smoother cycling.
Conclusion: The 20-Inch Advantage
The 20-inch barrel for an AR-15 platform provides a robust combination of accuracy, velocity, and effective range, making it an excellent option for shooters prioritizing precision and longer-distance capabilities. By understanding its advantages and carefully choosing the right barrel profile and material, you can optimize the performance of your AR-15 for your specific needs. Remember to always prioritize safety and follow all applicable firearm handling regulations.