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Subsonic Loads for the 45-70: A Comprehensive Guide

The 45-70 Government cartridge, originally designed for the U.S. military’s Springfield Model 1873 rifle, has enjoyed a remarkable resurgence in popularity. While known for its potent, full-power loads capable of taking down large game, an increasing number of shooters are exploring the benefits of subsonic loads for the 45-70. This article delves into the world of subsonic 45-70 ammunition, examining its advantages, considerations, and practical applications.

Understanding Subsonic Ammunition

Before diving into the specifics of the 45-70, it’s crucial to understand what defines subsonic ammunition. Subsonic ammunition is designed to propel a bullet at a velocity below the speed of sound, which is roughly 1,125 feet per second (fps) at sea level and standard temperature. This is primarily achieved by using lighter powder charges and heavier bullets. The result is a significantly quieter shot, reduced recoil, and a different set of ballistic characteristics compared to supersonic rounds.

The Allure of Subsonic 45-70 Loads

Why would someone choose to load the mighty 45-70 to subsonic velocities? Several compelling reasons exist:

Noise Reduction: This is the most significant advantage. A supersonic bullet breaks the sound barrier, creating a loud sonic boom. Subsonic rounds eliminate this, resulting in a much quieter report, especially when paired with a suppressor. This is beneficial for hunters, recreational shooters, and those concerned about noise pollution.
Reduced Recoil: Lower velocity means less recoil. Subsonic 45-70 loads offer a more comfortable shooting experience, particularly for extended range sessions or for shooters sensitive to recoil.
Target Shooting and Practice: Subsonic loads are ideal for target practice and honing shooting skills without the jarring recoil and loud noise of full-power rounds. They allow for more controlled and consistent shooting.
Hunting Applications: While not suitable for all game, subsonic 45-70 rounds can be effective for close-range hunting of smaller game like deer or wild hogs, particularly when stealth is paramount. Shot placement becomes even more critical due to the reduced velocity and energy.
Suppressed Shooting: The 45-70, when paired with a suppressor and subsonic loads, becomes an exceptionally quiet platform. This is particularly useful for pest control or hunting in areas where noise is a concern.

Considerations for Loading Subsonic 45-70

Developing and using subsonic loads for the 45-70 requires careful attention to detail. Here are some key considerations:

Bullet Weight: Heavier bullets are generally preferred for subsonic 45-70 loads. They maintain momentum better at lower velocities and provide adequate terminal performance. Projectiles in the 400-500 grain range are common.
Powder Selection: Choosing the right powder is crucial. Powders that burn cleanly and consistently at low pressures are essential for reliable ignition and accuracy. Trail Boss, Accurate 5744, and IMR 4198 are popular choices.
Load Data: Always consult reliable reloading manuals or online resources for tested and verified load data. Starting loads should be carefully worked up, monitoring for signs of overpressure or squib loads (where the bullet doesn’t exit the barrel).
Chronographing: A chronograph is an invaluable tool for developing subsonic 45-70 loads. It allows you to accurately measure the bullet’s velocity and ensure it remains below the speed of sound.
Accuracy Testing: Once you have a load that chronographs within the desired velocity range, accuracy testing is essential. Experiment with different bullet seating depths and powder charges to find the most accurate combination for your rifle.
Rifle Twist Rate: The twist rate of your rifle’s barrel can affect the stability of heavier bullets at subsonic velocities. A faster twist rate (e.g., 1:20) is generally better for stabilizing heavier projectiles.
Bullet Expansion: At subsonic velocities, bullet expansion can be unreliable. Choose bullets designed for low-velocity expansion or consider using cast lead bullets that deform upon impact.

Choosing the Right Components

Selecting the appropriate components is vital for safe and effective subsonic 45-70 loading. Here’s a closer look:

Bullets

As mentioned earlier, heavier bullets are typically preferred. Look for bullets specifically designed for subsonic use or cast lead bullets. Some popular choices include:

Cast Lead Bullets: These are a cost-effective option and often provide good accuracy at subsonic velocities. Look for bullets with a flat nose or wide meplat for increased terminal performance.
Specialized Subsonic Bullets: Some manufacturers offer bullets specifically designed for subsonic loads. These bullets often feature a hollow point or other design features to promote expansion at lower velocities.
Coated Bullets: Polymer-coated lead bullets can reduce leading in the barrel, which can be a concern with cast lead bullets, especially at higher pressures (even in subsonic loads).

Powder

The right powder is critical for consistent and reliable ignition at low pressures. Some recommended powders include:

Trail Boss: This powder is specifically designed for reduced loads and is a popular choice for subsonic 45-70. It’s bulky and fills the case well, which helps prevent double charges.
Accurate 5744: This powder is another excellent option for reduced loads. It burns cleanly and consistently, providing good accuracy.
IMR 4198: While typically used for full-power loads, IMR 4198 can also be used for subsonic 45-70, but careful load development is required.

Primers

Standard large rifle primers are generally suitable for subsonic 45-70 loads. However, some reloaders prefer to use magnum primers to ensure reliable ignition, especially in cold weather.

Developing Your Subsonic 45-70 Load

Developing a safe and accurate subsonic 45-70 load requires a methodical approach. Follow these steps:

Consult Reloading Manuals: Start by consulting reliable reloading manuals or online resources for published load data.
Start Low: Always begin with the starting load and gradually work up, monitoring for signs of overpressure or squib loads.
Use a Chronograph: Use a chronograph to measure the bullet’s velocity and ensure it remains below the speed of sound.
Adjust Powder Charge: Adjust the powder charge in small increments until you achieve the desired velocity.
Accuracy Testing: Once you have a load that chronographs within the desired velocity range, accuracy testing is essential. Shoot groups at a known distance (e.g., 50 or 100 yards) to assess the load’s accuracy.
Experiment with Seating Depth: Experiment with different bullet seating depths to fine-tune accuracy.
Record Your Results: Keep detailed records of your load development process, including powder charges, bullet weights, velocities, and accuracy results.

Safety Precautions

Reloading ammunition can be dangerous if not done properly. Always follow these safety precautions:

Wear Safety Glasses: Always wear safety glasses when reloading ammunition.
Follow Reloading Manuals: Always follow the instructions and recommendations in reliable reloading manuals.
Use Accurate Scales: Use accurate scales to weigh powder charges.
Double-Check Your Work: Double-check your work to ensure that you are using the correct components and powder charges.
Store Components Safely: Store reloading components in a safe and secure location.

Commercial Subsonic 45-70 Ammunition

While reloading is a popular option for creating subsonic 45-70 loads, several manufacturers also offer commercially loaded ammunition. These rounds are typically loaded with heavy bullets and low-pressure powders to achieve subsonic velocities. Some popular brands include:

Buffalo Bore Ammunition: Buffalo Bore offers a variety of subsonic 45-70 loads designed for hunting and self-defense.
Black Hills Ammunition: Black Hills also produces subsonic 45-70 ammunition, known for its quality and accuracy.
Fiocchi Ammunition: Fiocchi provides subsonic 45-70 options as well.

Purchasing commercially loaded ammunition can be a convenient option for those who do not reload or who want to try subsonic 45-70 without investing in reloading equipment.

Conclusion

Subsonic loads for the 45-70 offer a unique and versatile shooting experience. Whether you’re looking to reduce noise and recoil, practice your shooting skills, or hunt smaller game, subsonic 45-70 can be a valuable addition to your shooting repertoire. By understanding the principles of subsonic ammunition, carefully selecting your components, and following safe reloading practices, you can unlock the full potential of this iconic cartridge in a quieter and more manageable form. Remember to always consult reputable reloading manuals and resources, and prioritize safety above all else. [See also: Reloading for Precision Shooting] [See also: Best Suppressors for 45-70] [See also: 45-70 Ballistics Explained]