The .45-70 Government cartridge, a venerable round with a rich history, is experiencing a resurgence in popularity. Its substantial stopping power makes it a favorite for hunting large game, while its relatively low recoil makes it manageable for many shooters. However, many are exploring the benefits of subsonic .45-70 loads, offering distinct advantages in specific situations. This guide delves into the world of subsonic 45-70 load data, providing crucial information for safe and effective reloading.
Understanding Subsonic Ammunition
Subsonic ammunition is designed to travel slower than the speed of sound (approximately 1125 feet per second or 343 meters per second). This characteristic offers several benefits:
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Reduced Noise: The primary advantage is significantly reduced noise. This is crucial for hunting in noise-sensitive areas or for stealth operations. The lack of a sonic boom makes it much quieter than supersonic rounds.
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Improved Accuracy: Subsonic rounds can exhibit improved accuracy, particularly at longer ranges, due to less air resistance and decreased bullet instability at supersonic velocities.
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Increased Effectiveness with Suppressors: Subsonic ammunition is optimized for use with suppressors or sound moderators. The lower velocity minimizes the amount of gas escaping the barrel, resulting in a more effective suppression. This reduces the report to an almost inaudible level.
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Specific Applications: Certain applications, like hunting close-range game, might favor subsonic loads for the reduced risk of overpenetration.
Choosing the Right Components for Subsonic 45-70 Loads
Creating subsonic .45-70 loads requires careful selection of components. The wrong combination can lead to inconsistent performance or even dangerous pressure issues.
Bullets:
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Heavy Bullets: Heavier bullets (400 grains and above) are essential for achieving subsonic velocities. This added weight helps maintain momentum and energy even at lower velocities. Popular choices include lead bullets designed specifically for subsonic use. Look for bullets with a relatively low ballistic coefficient.
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Bullet Design: The bullet design plays a significant role. A round-nose or flat-nose design is preferred for subsonic applications. These bullet shapes minimize aerodynamic instability at lower velocities. Avoid hollow-point bullets unless specifically designed for subsonic use, as their performance can be unpredictable.
Powders:
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Slow-Burning Powders: Subsonic loads necessitate slow-burning powders. These powders are designed to burn at a slower rate, providing consistent pressure at lower velocities. Some common powders used in subsonic .45-70 loads include IMR 4198, IMR 4227, and Trail Boss. Always check your reloading manual for recommended powder charges.
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Accurate Measurement: Precise powder measurement is critical for safety and consistency. Use a reliable powder scale and double-check your measurements before loading each cartridge.
Cases:
- Case Condition: Using properly sized and prepared cases is paramount for safety and accuracy. Inspect cases for any damage or imperfections before loading. Ensure they are clean and properly sized.
Primers:
- Standard Primers: Standard large rifle primers are typically used for subsonic .45-70 loads. Avoid using magnum primers unless specifically recommended in a reloading manual.
Sample Subsonic 45-70 Load Data
Disclaimer: The following load data is for informational purposes only. Always consult a reputable reloading manual and adhere to its guidelines. Never exceed the maximum recommended load data. Improperly loaded ammunition can result in serious injury or death.
| Bullet Weight (Grains) | Powder (Grains) | Primer | Velocity (fps) | Pressure (PSI) | Notes |
|---|---|---|---|---|---|
| 405 gr RN | 20 gr IMR 4198 | Large Rifle | 950 | (Consult Manual) | Test Loads |
| 405 gr RN | 22 gr IMR 4227 | Large Rifle | 900 | (Consult Manual) | Test Loads |
| 500 gr RN | 18 gr Trail Boss | Large Rifle | 850 | (Consult Manual) | Test Loads |
Note: The pressure values are not provided in this table because they will vary considerably depending on the specific components and equipment used. You must consult a reliable reloading manual for accurate pressure data for your specific setup.
This is not an exhaustive list and should not be used without thorough review of other reloading manuals.
Safety Precautions for Reloading Subsonic 45-70 Ammunition
Reloading ammunition, even subsonic loads, requires meticulous attention to safety.
- Read and Understand Your Reloading Manual: Always consult a reputable reloading manual specific to your equipment and components. Follow its instructions carefully.
- Proper Equipment: Use appropriate reloading equipment in good working order.
- Precise Measurements: Double-check all your measurements.
- Cleanliness: Maintain a clean and organized workspace.
- Test Loads: Always start with test loads and gradually work up to your desired velocity.
- Chronicling Loads: Keep accurate records of your load data.
- Proper Storage: Store your ammunition in a cool, dry, and safe location.
Conclusion: Subsonic 45-70 Reloading
Subsonic .45-70 load data offers unique advantages for specific shooting situations. By carefully selecting components and following safe reloading practices, you can create effective and quiet ammunition ideal for hunting, plinking, or other applications. However, always prioritize safety and consult reputable sources for accurate and safe reloading information. This guide provides a starting point, but the responsibility for safe reloading rests entirely with the reloader.