The .308 Winchester (7.62x51mm NATO) cartridge is a popular choice for both hunting and long-range shooting, and the barrel length plays a crucial role in its performance. A 20-inch barrel is a common length for this caliber, offering a balance between portability, accuracy, and velocity. This article explores the nuances of a 308 20 inch barrel, examining its ballistic characteristics, suitability for various applications, and factors to consider when choosing one.
Ballistics and Performance of a 308 20 Inch Barrel
The velocity of a bullet is significantly influenced by the barrel length. A longer barrel allows more time for the expanding gases to propel the bullet, resulting in higher muzzle velocity. While a 20-inch barrel won't achieve the extreme velocities of longer barrels (e.g., 24" or 26"), it still provides sufficient energy for many applications.
Velocity and Energy Comparison (Approximate):
Let's compare the approximate muzzle velocity and energy of a 150-grain .308 bullet fired from different barrel lengths:
| Barrel Length (inches) | Muzzle Velocity (fps) | Muzzle Energy (ft-lbs) |
|---|---|---|
| 16 | 2700 | 2600 |
| 20 | 2800 | 2850 |
| 24 | 2900 | 3050 |
Note: These values are estimates and can vary depending on the specific ammunition, powder load, and barrel twist rate.
The 20-inch barrel delivers a good balance. It provides enough velocity for effective hunting at moderate ranges and delivers sufficient energy for target shooting. The slightly lower recoil compared to longer barrels makes it easier to manage, especially for less experienced shooters.
Accuracy and Precision
Barrel length also impacts accuracy. While a longer barrel generally offers better accuracy due to more complete powder burn, a 20-inch barrel is more than adequate for many shooters. Precision is greatly affected by factors beyond barrel length, including ammunition quality, scope mounting, and shooter skill.
A well-made 20-inch barrel can easily achieve sub-MOA (Minute of Angle) accuracy, meaning groups of shots will cluster within a 1-inch circle at 100 yards. This is more than sufficient for most hunting and recreational shooting needs.
Applications of a 308 20 Inch Barrel
The versatility of the .308 Winchester cartridge, combined with the manageable length of a 20-inch barrel, makes it suitable for a wide range of applications:
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Hunting: A 20-inch barrel is ideal for hunting deer, hogs, and other medium-sized game at typical hunting ranges. The balance between power and maneuverability makes it a practical choice for hunting in various terrains.
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Tactical Shooting: The shorter barrel is advantageous in close-quarters situations where maneuverability is critical. It is also a popular choice for designated marksmen and other tactical roles.
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Long-Range Shooting (with limitations): While not ideal for extreme long-range shooting, a 20-inch barrel can provide sufficient accuracy for shots out to several hundred yards, especially with high-quality ammunition and a good scope.
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Competition Shooting: Depending on the specific competition rules, a 20-inch barrel can be a competitive choice in various shooting disciplines.
Choosing a 308 20 Inch Barrel: Factors to Consider
Several factors should be considered when choosing a 20-inch barrel for your .308 rifle:
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Barrel Material: Common materials include stainless steel (resistant to corrosion), chrome-moly (a good balance of strength and cost), and carbon fiber (lighter weight, but often more expensive).
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Twist Rate: The twist rate (how many inches it takes for the rifling to complete one full rotation) affects bullet stability. A 1:10 or 1:12 twist rate is common for .308 and is generally suitable for a wide range of bullet weights.
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Profile: Different barrel profiles (contour) impact weight, heat dissipation, and stiffness. Heavy barrels are more accurate but heavier to carry, while lighter profiles are easier to maneuver but might be less accurate at high rates of fire.
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Manufacturer Reputation: Choose a reputable manufacturer known for producing high-quality barrels with consistent accuracy and longevity.
Conclusion: A Balanced Choice
The 308 20 inch barrel represents a solid compromise between performance and portability. Its suitability for various applications, combined with its manageable size and weight, makes it a popular choice among hunters, tactical shooters, and recreational enthusiasts alike. By carefully considering the factors outlined above, you can choose a 20-inch barrel that will meet your specific needs and provide years of reliable service.