The .308 Winchester, a popular cartridge known for its accuracy and stopping power, finds a niche application in subsonic loads. This guide delves into the reasons behind choosing subsonic .308, the benefits, drawbacks, and a detailed look at achieving optimal subsonic performance.
Why Choose Subsonic .308?
Subsonic ammunition, traveling slower than the speed of sound (approximately 1125 feet per second or 343 meters per second), offers several advantages, particularly in specific scenarios:
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Reduced Noise: The primary benefit is significantly reduced noise signature. This is crucial for hunting situations where noise could spook game, or for tactical applications where stealth is paramount.
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Suppressed Shooting: Subsonic rounds are ideal for use with suppressors. Supersonic ammunition generates a loud "crack" upon exiting the barrel, even with a suppressor. Subsonic loads minimize this "crack," resulting in a much quieter shooting experience.
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Increased Accuracy (Potentially): In some cases, subsonic loads can exhibit improved accuracy at longer ranges due to reduced bullet instability caused by supersonic flight. However, this is dependent on the specific bullet design and load.
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Specialized Applications: Certain applications, such as hunting at close range in urban areas or situations requiring extreme stealth, are better served by subsonic ammunition.
Understanding the Challenges of Subsonic .308
While subsonic .308 offers clear advantages, there are inherent challenges:
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Reduced Range and Energy: The lower velocity translates to a shorter effective range and reduced stopping power compared to supersonic loads. This is a significant consideration, particularly for hunting larger game.
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Bullet Selection: Proper bullet selection is critical for reliable feeding and function. Heavier bullets are generally required to achieve subsonic velocities while maintaining sufficient energy for target impact.
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Powder Selection: Finding the correct powder is essential to ensure consistent and reliable ignition at lower pressures. Certain powders are better suited for subsonic loads than others.
Building Subsonic .308 Loads: A Step-by-Step Guide
Disclaimer: Reloading ammunition involves inherent risks. Always adhere to safety precautions, consult reloading manuals, and practice responsible gun handling. This information is for educational purposes only, and I am not responsible for any injuries or damages resulting from reloading activities.
1. Components:
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Cases: High-quality .308 Winchester brass cases are essential.
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Bullets: Heavier bullets (typically 180-220 grains) are necessary to maintain sufficient energy at subsonic speeds. Lead-core, jacketed hollow-point, and full metal jacket options are available, each offering unique performance characteristics.
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Powder: Careful powder selection is critical for subsonic loads. Slow-burning powders like Titegroup, Longshot, or Accurate #5 are often used, but consult reloading manuals for specific recommendations and safe load data.
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Primers: Standard rifle primers will generally suffice.
2. Reloading Process:
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Case Preparation: Resize, deprime, and clean your cases thoroughly.
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Charge Weighing: Precisely measure your powder charge using a scale. This is crucial for safe and consistent results. Always refer to reloading manuals for recommended powder charges.
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Bullet Seating: Seat the bullet to the proper depth as specified in your reloading data.
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Crimp: Apply a proper crimp to ensure the bullet is securely seated.
3. Load Development:
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Start Low: Begin with the minimum powder charge listed in your reloading manual.
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Gradually Increase: Incrementally increase the powder charge, carefully observing the results. Pay attention to pressure signs (flat primers, excessive case expansion).
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Chronograph: Use a chronograph to measure the velocity of your rounds. Adjust your load to achieve subsonic velocities while maintaining consistent accuracy.
4. Testing:
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Function Testing: Test your loads at the range to ensure reliable feeding and function in your firearm.
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Accuracy Testing: Determine the accuracy of your handloads at various ranges.
Conclusion:
Subsonic .308 loads offer a unique set of advantages for specific applications where noise reduction and stealth are paramount. However, understanding the limitations, selecting the correct components, and carefully following reloading procedures are critical for safe and effective results. Remember, safety is paramount, always consult reloading manuals, and start low and go slow. With careful planning and execution, you can successfully create reliable and effective subsonic .308 ammunition.
