Understanding Subsonic Ballistics
Defining Subsonic
Before venturing into the specifics of Hornady .308 subsonic loads, it is crucial to establish a foundation in subsonic ballistics. The term “subsonic” simply means that the projectile’s velocity is below the speed of sound. This speed varies depending on atmospheric conditions, but it hovers around the neighborhood of roughly 1125 feet per second (fps) at sea level. When a bullet travels slower than the speed of sound, it eliminates the sonic boom that accompanies supersonic projectiles. This sonic absence is a significant advantage, particularly when using a suppressor or when the goal is to minimize noise signature.
Subsonic vs. Supersonic Differences
The behavior of a subsonic projectile differs from its supersonic counterpart. Supersonic bullets create a shockwave as they travel, affecting their trajectory and wind drift characteristics. Subsonic rounds, lacking this shockwave, generally experience greater drop over distance and are more susceptible to wind influence. This means that accurate range estimation and wind doping become even more critical when shooting subsonic rounds. The trajectory of a subsonic bullet curves more significantly downwards compared to a supersonic bullet. Therefore, it’s important to zero your rifle at a specific distance for these loads, and understand how much you must adjust your point of aim at varying distances. Wind drift becomes another consideration. The lower velocity gives the wind more time to influence the bullet’s path.
Key Factors for Subsonic Loads
Achieving consistent subsonic velocities requires careful consideration of several factors. The weight of the bullet plays a pivotal role, with heavier bullets generally favored for subsonic applications. Furthermore, the design of the bullet, particularly its profile and construction, affects its ballistic coefficient and its ability to stabilize at lower velocities. The selection of the appropriate powder is equally important. Fast-burning powders are often preferred because they burn completely and efficiently at lower velocities. This provides the necessary energy to propel the bullet to its intended subsonic speed without generating excessive pressure.
Hornady Bullets for Subsonic .308 Loads
Choosing the Right Bullet
Hornady, a name synonymous with quality and innovation in ammunition and reloading components, offers a selection of bullets perfectly suited for .308 subsonic loads. Choosing the right bullet is crucial for optimal performance.
ELD-Match
One excellent choice is the ELD-Match bullet. The ELD-Match (Extremely Low Drag Match) line is specifically designed for accuracy and long-range performance. While they might not have been designed specifically for subsonic use, their consistent performance, precise construction, and high ballistic coefficient make them suitable for quiet, accurate shooting. The ELD-Match bullets typically provide excellent accuracy, even at subsonic velocities, making them a favorite among target shooters.
A-MAX
The A-MAX bullet, though discontinued, was another excellent choice from Hornady. These bullets were highly regarded for their accuracy and high ballistic coefficient, making them suitable for subsonic applications. If you happen to have access to them, they’re well worth considering.
Sub-X
A dedicated subsonic bullet designed by Hornady is the Sub-X (Subsonic eXpanding) bullet. This bullet is engineered to expand reliably at subsonic velocities. Its design, which often incorporates a Flex Tip, is optimized for expansion, ensuring effective terminal performance in the target. The Sub-X is an ideal choice for hunters and those who require maximum terminal effect.
Other Hornady Bullet Options
Other Hornady bullets can be used for subsonic loads, particularly those with a specific design. HPBT (Hollow Point Boat Tail) and FMJ (Full Metal Jacket) bullets, may be suitable depending on the desired use. The goal is to find a balance between weight, ballistic coefficient, and terminal performance.
Bullet Weight Considerations
Bullet weight recommendations for .308 subsonic loads typically fall within a certain range. Heavier bullets, such as those weighing 190 grains, 200 grains, or even over 220 grains, are often favored. The increased mass provides a greater sectional density and better stability at subsonic speeds. However, it is important to match bullet weight with the rifle’s barrel twist rate.
Powder Selection for Hornady .308 Subsonic Loads
Importance of Powder Choice
Selecting the appropriate powder is vital when handloading .308 subsonic ammunition. The chosen powder must provide the necessary energy to propel the bullet to the desired subsonic velocity without creating excessive pressure within the cartridge.
Fast-Burning Powders
Fast-burning powders are generally preferred for subsonic applications. These powders burn quickly, efficiently, and completely at lower velocities, producing the required energy to launch the bullet. Specific powder examples include Hodgdon Titegroup, which is a fast-burning pistol powder that can be useful for subsonic loads, and Accurate No. 7. Remember to always follow the manufacturer’s load data.
Safety First
It is important to emphasize that these are just examples, and the specific powder choice should always be based on the load data and the desired performance characteristics. Always consult reliable reloading manuals or online resources for specific powder recommendations.
It is paramount to prioritize safety when handloading. Never exceed the maximum powder charge listed in your reloading manuals. Exceeding these maximums can lead to dangerous pressure spikes that could damage your firearm and cause serious injury. When starting a new load, always begin with the minimum recommended powder charge and carefully work your way up while observing the signs of pressure.
Hornady .308 Subsonic Load Data
**Important Safety Disclaimer:** Before embarking on any handloading activity, it is imperative to emphasize that reloading ammunition carries inherent risks. This information is for informational purposes only and does not constitute a recommendation or endorsement of any specific load data. *ALWAYS* consult reliable, current reloading manuals published by reputable companies (like Hornady, Lyman, Sierra, etc.) and follow all safety precautions. Handloading is a potentially dangerous activity. The author of this article is not responsible for any accidents, injuries, or damages resulting from the use of this information. Always wear appropriate safety glasses and hearing protection during the loading and shooting process. Start with the minimum powder charge listed in your chosen reloading manual and work your way up gradually, carefully monitoring for any signs of excessive pressure, such as flattened primers, difficult bolt extraction, or ejector marks on the case head. Chronograph your loads to verify velocity.
Load Data Tables
*Note: This is a hypothetical table; always consult a reputable reloading manual for verified load data.*
*This table is provided for example purposes only. Always consult current reloading manuals and start with minimum powder charges.*
| Bullet Type (Hornady) | Bullet Weight (Grains) | Powder (Example) | Starting Charge (Grains) | Max Charge (Grains) | Primer Type | Case Type | OAL (inches) | Estimated Velocity (fps) | Notes |
|---|---|---|---|---|---|---|---|---|---|
| Hornady ELD-Match | 190 | Hodgdon Titegroup | 4.0 | 5.0 | CCI 34 | Winchester | 2.800 | 1050 – 1100 | Check for keyholing |
| Hornady ELD-Match | 190 | Accurate No. 7 | 6.5 | 7.5 | CCI 34 | Winchester | 2.800 | 1075 – 1150 | Test in your rifle |
| Hornady Sub-X | 200 | Hodgdon Titegroup | 3.8 | 4.8 | CCI 34 | Winchester | 2.800 | 1000 – 1075 | Consider expansion at target |
| Hornady Sub-X | 200 | Accurate No. 7 | 6.0 | 7.0 | CCI 34 | Winchester | 2.800 | 1025 – 1100 | Verify cycling in semi-automatic rifles |
| Hornady ELD-Match | 220 | Hodgdon Titegroup | 3.5 | 4.5 | CCI 34 | Winchester | 2.800 | 950 – 1025 | May require slower twist rate |
| Hornady Sub-X | 200 | Winchester 231 | 4.0 | 5.0 | CCI 34 | Winchester | 2.800 | 1000 – 1075 | Check for signs of overpressure |
*These are approximate values and serve as examples only. Consult your chosen reloading manual for specific data.*
The above tables provide sample load data. The key to successful reloading lies in finding the load that works best for your rifle and your specific needs. Remember to consult multiple sources and always begin with the minimum charge.
Handloading Best Practices for .308 Subsonic
Case Preparation
Producing consistent and safe subsonic loads depends heavily on adhering to best practices. Attention to detail is crucial throughout the entire process.
Case preparation is paramount. Begin by inspecting your brass cases for any damage or defects. Clean the cases thoroughly, removing any dirt or debris that may affect the loading process. Trimming the cases to the correct length ensures consistency in overall cartridge length (OAL). Chamfering and deburring the case mouth eases bullet seating and minimizes the risk of bullet damage. Priming your brass can be done with hand tools or a loading press.
Seating Depth
Seating depth also plays a crucial role in subsonic performance. Proper seating depth directly affects the internal case volume and the pressure generated. Consistent seating depth will minimize variations in velocity. The OAL is especially crucial for achieving the desired subsonic velocity. Ensure that your OAL conforms to the specifications of your rifle and is short enough to prevent the bullet from touching the rifling.
Chronographing
A chronograph is an indispensable tool when working with subsonic loads. It allows you to measure the velocity of your loads accurately. Place your chronograph at the recommended distance. When establishing subsonic loads, a chronograph provides immediate feedback on whether your loads are achieving the intended velocity. Record your results for each load, making sure to note your powder charge, bullet type, and any other relevant details.
Accuracy Testing
Testing for accuracy is an essential component of the reloading process. At a safe range with appropriate targets, assess the accuracy of your loads. Begin by firing a few groups at a target at your desired distance. Adjust your point of aim to compensate for bullet drop and wind drift.
Using Subsonic .308 Loads
Advantages of Subsonic Loads
Subsonic .308 loads offer several distinct advantages, opening doors to specialized applications. The primary benefit is a significant reduction in noise. When combined with a suppressor, subsonic ammunition can create an exceptionally quiet shooting experience. This quiet nature is advantageous in situations where noise is a concern.
The reduced recoil associated with subsonic loads also makes them an excellent option for beginners or shooters sensitive to recoil. This smoother shooting experience can also improve accuracy.
Hunting Considerations
Subsonic loads can be used for hunting. However, appropriate bullet selection is critical.
Range Limitations
The effective range of subsonic .308 loads is generally limited compared to supersonic rounds. Subsonic bullets experience greater drop over distance. Compensating for this drop requires precise range estimation and adjustment to your point of aim. However, for applications within shorter ranges, subsonic .308 loads can provide accuracy.
Troubleshooting
Keyholing
Even with careful reloading practices, you may encounter certain issues. Understanding how to troubleshoot these problems is crucial to safe and effective shooting.
Keyholing occurs when a bullet fails to stabilize in flight, causing it to tumble and strike the target sideways. Keyholing indicates a lack of gyroscopic stability, often caused by a combination of factors such as bullet weight, barrel twist rate, or inadequate powder charge. Selecting a bullet of the proper weight for your rifle’s twist rate is essential.
Inconsistent Accuracy
Inconsistent accuracy may be caused by several factors, including inconsistent powder charges, bullet seating depth variations, or poor-quality bullets. Ensure that you weigh your powder charges accurately. Verify that all cases are trimmed to the same length.
Cycling Issues
Failure to cycle is a common problem when using subsonic loads in semi-automatic rifles. The reduced pressure generated by subsonic loads may not generate enough force to cycle the action reliably. This is often mitigated by adjusting the gas system and choosing a suitable powder.
Safety Considerations: The Foundation of Responsible Handloading
Safety must be the overriding priority throughout the handloading process. Following established safety protocols protects you and those around you.
Always start with the minimum recommended powder charge in your reloading manual and gradually increase the charge. This gradual approach prevents the possibility of overpressure.
If you notice any signs of pressure, such as flattened primers, difficult bolt extraction, or bulging cases, immediately stop loading and disassemble the ammunition.
Use only high-quality, calibrated equipment, including scales, calipers, and a chronograph.
Always wear appropriate safety gear, including safety glasses and hearing protection, during both the loading and shooting processes.
Conclusion
Hornady .308 subsonic loads offer a fascinating avenue for shooters seeking quietness, reduced recoil, and specialized performance. By understanding subsonic ballistics, selecting appropriate Hornady bullets and powders, and adhering to safe handloading practices, you can achieve exceptional results. Remember to consult reloading manuals and always prioritize safety.
The world of handloading is dynamic. New bullet designs, powders, and reloading techniques are constantly emerging. Remain informed, and stay up to date on the latest developments in the world of subsonic ammunition.
Disclaimer
This article provides informational content only. Reloading ammunition is a potentially dangerous activity. Always consult reliable reloading manuals and adhere to all safety guidelines. The author is not responsible for any injuries or damages resulting from the use of this information. Handloading carries inherent risks and must be approached with caution and respect for the process.
Resources
For more information, consider the following:
Hornady Website (for bullet and reloading information): [Insert Hornady Website Link Here]
Lyman Reloading Manual: [Insert link for a reputable reloading manual]
Sierra Bullets Website: [Insert Sierra Bullets Website Link]
Reloading Forums: [Insert links to reputable handloading forums]
By following these guidelines and embracing a commitment to safety and precision, you can enjoy the unique advantages offered by Hornady .308 subsonic loads.
