Accurate 1680 Load Data for 300 Blackout: Maximize Performance and Safety

May 9, 2025September 1, 2024 by Cornelius

Table of Contents

Understanding the 300 Blackout Cartridge

The Birth of the 300 Blackout

The 300 Blackout cartridge has taken the shooting world by storm, and it’s easy to see why. With its versatility, the ability to be suppressed effectively, and remarkable performance in a compact package, it’s a favorite among hunters, tactical shooters, and recreational enthusiasts alike. But to truly unlock the potential of this exciting cartridge, careful handloading practices are a must.

Flexibility and Applications

Born from the desire to fit more power into the AR-15 platform, the 300 Blackout (also known as 300 BLK) began its journey with the intention of offering superior ballistics compared to the 5.56 NATO, especially when suppressed. Its design allowed the shooter to switch between supersonic loads, ideal for hunting and general purpose shooting, and subsonic loads, which shine with the use of a suppressor.

Popularity and Advantages

The cartridge’s popularity grew rapidly, thanks to its performance in a variety of roles. Hunters found the 300 Blackout effective for medium-sized game. Law enforcement and military personnel appreciated its compact size and suppression capabilities. Recreational shooters, too, enjoyed its accuracy and versatility, making it a great choice for plinking and range time. The cartridge’s adaptability has solidified its place as a leading choice for modern firearm enthusiasts.

All About Accurate 1680 Powder

Powder Overview

When it comes to reloading the 300 Blackout, selecting the right powder is paramount. Accurate 1680 is a key player in the 300 Blackout handloading community, praised for its consistent performance, especially when loading both supersonic and subsonic rounds. This powder, an extruded type, is manufactured with a specific grain size and shape to promote clean burning and efficient energy transfer, making it an excellent choice for the 300 Blackout.

Burn Rate and Versatility

The burn rate of Accurate 1680 is well-suited to the cartridge’s unique characteristics. Its burn rate is fast enough to achieve good velocities with heavier bullets, yet still offers good performance at subsonic speeds, making it a versatile choice.

Key Characteristics

Grain Shape and Size: The consistent grain geometry allows for even powder distribution within the case, which results in more uniform ignition.
Density: The powder’s density contributes to consistent metering and fill in the cartridge case, impacting performance and consistency.
Temperature Sensitivity: While no powder is completely insensitive to temperature, Accurate 1680 shows a level of stability that helps maintain consistency across a range of temperatures, which is beneficial for reloaders.

Safety is the Foundation: Essential Reloading Precautions

Before diving into any load data, it’s crucial to emphasize the non-negotiable importance of safe reloading practices. Reloading ammunition involves working with potentially dangerous materials. Improper techniques or a lapse in judgment can lead to serious injury, or damage to firearms, or both.

Essential Equipment and Practices

Eye Protection: Always wear safety glasses or goggles while reloading. This is the absolute most critical safety rule.
Gloves: While not always essential, gloves are recommended to protect your hands from powder residue and solvents.
Proper Ventilation: Reload in a well-ventilated area to avoid inhaling powder fumes.
Starting Low and Working Up: This cannot be stressed enough. Always start with the lowest recommended load and work up gradually, carefully observing the results. Never exceed published maximum loads.
Case Preparation: Proper case preparation is vital. This includes thorough cleaning, trimming the cases to the correct length, and chamfering/deburring the case mouths.
Accurate Measurements: Use calibrated scales and tools for precise measurements of powder charges and overall cartridge length. Inaccuracy in these measurements can be extremely dangerous.
Signs of Overpressure: Watch for telltale signs of excessive pressure, such as flattened primers, cratering primers, bulging of the case near the base, and difficult bolt extraction. If you observe any of these signs, immediately stop loading and consult a reloading manual.
Quality Components: Use only bullets, primers, and brass from reputable manufacturers. Never use unknown or questionable components.
Consult Manuals: Always cross-reference your data from at least one reliable reloading manual.

Optimizing Velocity: Accurate 1680 and Supersonic Loads

Disclaimer: The following load data is for informational purposes only. It is recommended that you always consult a reputable reloading manual and cross-reference any information before beginning your reloading. Always use the specific components (brass, primers, and bullets) that your manual lists. This information should never be a substitute for safe and responsible reloading practices.

When reloading 300 Blackout for supersonic performance, the goal is typically to maximize velocity while maintaining safe pressures and good accuracy. Accurate 1680 provides a good balance of speed and consistency.

Understanding how to interpret load data is important. You will find many different variables that contribute to a safe and effective load. For this article, you will find information on the following variables:

Bullet weight
Powder charge
Primer choice
Case type
Overall Cartridge Length (OAL)
Approximate Velocity

Load Data Examples

For commonly used bullet weights, here is some suggested starting data:

Medium Weight – 110 Grain Bullets

Starting Load of Accurate 1680: Consult a reloading manual for this specific starting load as it can vary.
Maximum Load of Accurate 1680: Consult a reloading manual for this specific maximum load as it can vary.
Estimated Velocity: Consult a reloading manual for the estimated velocity, as this can vary.
Recommended Primer: Consult a reloading manual for this specific primer recommendation as it can vary.
Recommended Case: Consult a reloading manual for the specific case recommendation as it can vary.
Overall Cartridge Length: Consult a reloading manual for the recommended OAL as it can vary.

A Common Choice – 125 Grain Bullets

Starting Load of Accurate 1680: Consult a reloading manual for this specific starting load as it can vary.
Maximum Load of Accurate 1680: Consult a reloading manual for this specific maximum load as it can vary.
Estimated Velocity: Consult a reloading manual for the estimated velocity, as this can vary.
Recommended Primer: Consult a reloading manual for this specific primer recommendation as it can vary.
Recommended Case: Consult a reloading manual for the specific case recommendation as it can vary.
Overall Cartridge Length: Consult a reloading manual for the recommended OAL as it can vary.

A good option – 135 Grain Bullets

Starting Load of Accurate 1680: Consult a reloading manual for this specific starting load as it can vary.
Maximum Load of Accurate 1680: Consult a reloading manual for this specific maximum load as it can vary.
Estimated Velocity: Consult a reloading manual for the estimated velocity, as this can vary.
Recommended Primer: Consult a reloading manual for this specific primer recommendation as it can vary.
Recommended Case: Consult a reloading manual for the specific case recommendation as it can vary.
Overall Cartridge Length: Consult a reloading manual for the recommended OAL as it can vary.

Heavier weight – 150 Grain Bullets

Starting Load of Accurate 1680: Consult a reloading manual for this specific starting load as it can vary.
Maximum Load of Accurate 1680: Consult a reloading manual for this specific maximum load as it can vary.
Estimated Velocity: Consult a reloading manual for the estimated velocity, as this can vary.
Recommended Primer: Consult a reloading manual for this specific primer recommendation as it can vary.
Recommended Case: Consult a reloading manual for the specific case recommendation as it can vary.
Overall Cartridge Length: Consult a reloading manual for the recommended OAL as it can vary.

Disclaimer: The loads listed above are for example only. Always consult a reputable reloading manual and carefully follow all safety precautions.

Subsonic Performance: Accurate 1680 and Quiet Precision

The allure of the 300 Blackout often lies in its subsonic capabilities. Combining a suppressor with subsonic loads provides a quiet shooting experience. Accurate 1680 can deliver impressive performance with these heavier bullet weights. Remember that, even with subsonic loads, safety remains the top priority.

Subsonic Load Examples

Here is a sample of suggested starting data for subsonic loads:

Heavy weight – 190 Grain Bullets

Starting Load of Accurate 1680: Consult a reloading manual for this specific starting load as it can vary.
Maximum Load of Accurate 1680: Consult a reloading manual for this specific maximum load as it can vary.
Estimated Velocity: Consult a reloading manual for the estimated velocity, as this can vary.
Recommended Primer: Consult a reloading manual for this specific primer recommendation as it can vary.
Recommended Case: Consult a reloading manual for the specific case recommendation as it can vary.
Overall Cartridge Length: Consult a reloading manual for the recommended OAL as it can vary.

Really Heavy – 200 Grain Bullets

Starting Load of Accurate 1680: Consult a reloading manual for this specific starting load as it can vary.
Maximum Load of Accurate 1680: Consult a reloading manual for this specific maximum load as it can vary.
Estimated Velocity: Consult a reloading manual for the estimated velocity, as this can vary.
Recommended Primer: Consult a reloading manual for this specific primer recommendation as it can vary.
Recommended Case: Consult a reloading manual for the specific case recommendation as it can vary.
Overall Cartridge Length: Consult a reloading manual for the recommended OAL as it can vary.

Maximum weight – 220 Grain Bullets

Starting Load of Accurate 1680: Consult a reloading manual for this specific starting load as it can vary.
Maximum Load of Accurate 1680: Consult a reloading manual for this specific maximum load as it can vary.
Estimated Velocity: Consult a reloading manual for the estimated velocity, as this can vary.
Recommended Primer: Consult a reloading manual for this specific primer recommendation as it can vary.
Recommended Case: Consult a reloading manual for the specific case recommendation as it can vary.
Overall Cartridge Length: Consult a reloading manual for the recommended OAL as it can vary.

Disclaimer: The loads listed above are for example only. Always consult a reputable reloading manual and carefully follow all safety precautions.

The Reloading Process and Tips for Success

The reloading process is a series of steps that, when followed correctly, produce accurate and safe ammunition.

Reloading Steps

Case Preparation: Start by cleaning the cases thoroughly to remove any dirt or debris. Next, trim the cases to the correct length. This helps to ensure consistent neck tension on the bullet and reliable performance. Finally, chamfer the case mouths to make seating the bullet easier and to prevent damage to the bullet.
Priming: Insert a new primer into the primer pocket using a priming tool. Always ensure that the primer is seated flush with the case head.
Powder Charging: Using a calibrated powder measure, carefully charge the case with the correct amount of Accurate 1680 powder. This is the most critical step in the process; measuring powder accurately is essential for both accuracy and safety.
Bullet Seating: Seat the bullet to the correct overall cartridge length (OAL), which is specified in the reloading manual. Ensure that the bullet is seated straight.
Crimp (if needed): Some bullets require a crimp to ensure they stay in place during feeding and to provide more consistent ballistic performance. Follow the reloading manual’s instructions.

Additional Tips for Better Reloading

Case Selection: Choose brass from a reputable manufacturer, and try to use cases from the same production lot. This will help ensure consistent neck tension.
Seating Depth: Experiment with seating depth, as this can impact accuracy. The OAL recommendations in reloading manuals are a good starting point, but small adjustments can sometimes yield significant improvements.
Bullet Selection: Use high-quality bullets and, when reloading subsonic loads, make sure to select bullets designed for subsonic performance.
Powder Charging: Use a calibrated powder measure and carefully weigh each charge to ensure consistent charges.
Chronograph: Using a chronograph is highly recommended. It will provide you with real-time velocity data, which will help you determine if your loads are performing as expected and identify potential issues.

Troubleshooting Common Issues

Even with meticulous attention to detail, problems can occur during reloading. Knowing how to identify and address these issues is crucial for both safety and good results.

Common Problems and Solutions

Failure to Fire: This can be caused by several factors, including a faulty primer, insufficient powder charge, or a problem with the firing pin.
Extraction Problems: Difficult or incomplete extraction may be due to excessive pressure, a dirty chamber, or incorrect case sizing.
Inconsistent Velocities: Variable velocities can result from inconsistent powder charges, improper case preparation, or inconsistencies in the primers or bullets.
Signs of Overpressure: If you observe flattened primers, cratering primers, or difficult bolt extraction, STOP immediately. These are clear signs of excessive pressure, which can damage your firearm and cause serious injury.

If you encounter any of these problems, carefully review your reloading process and consult reliable resources such as reloading manuals or experienced reloaders to diagnose the issue.

Conclusion

Reloading the 300 Blackout with Accurate 1680 offers a rewarding experience for the serious shooter. The combination of the cartridge’s inherent versatility and the powder’s consistent performance can unlock impressive results. Whether you’re pursuing maximum velocity with supersonic loads or achieving whisper-quiet suppression with subsonic loads, the 300 Blackout offers many opportunities to hone your shooting skills.

But remember, safe reloading is paramount. Always prioritize safety, meticulously follow recommended load data from trusted sources, and carefully adhere to the reloading process. Responsible handloading is the cornerstone of a safe and enjoyable shooting experience.

Take the time to learn and understand the finer points of reloading. The information in this article is not a replacement for a full understanding of the subject and, in fact, is not the full extent of the subject itself.

Disclaimer/Legal Notice

This article is for informational purposes only. Reloading ammunition is inherently dangerous, and you must take full responsibility for your actions. The information provided in this article is based on commonly available resources and is intended to provide a general overview of reloading the 300 Blackout with Accurate 1680 powder.

Always prioritize your safety. Reloading improperly can cause serious injury or even death. Never exceed the maximum loads recommended in reputable reloading manuals. The author and publisher of this article are not responsible for any accidents, injuries, or damages resulting from the use of this information. Consult professional guidance if you are unsure about any aspect of reloading. Always consult with a licensed professional before modifying or loading ammunition for use in a firearm.

Resources

Hodgdon Reloading Data: A comprehensive source of powder and load data. (Link: [Insert Link if Available])
Lyman Reloading Handbook: A classic and reliable reloading manual.
Sierra Bullets Reloading Manual: A great resource for bullet-specific load data.
Accurate Powders Website: Official information about Accurate 1680 and other powders (Link: [Insert Link if Available]).
Reloading Forums and Online Communities: (Proceed with caution) Online forums and communities can offer advice, but always cross-reference any information obtained. Examples: [Insert example forum links if available].
Local Gun Clubs and Ranges: Many offer introductory classes and have experienced reloaders who can offer hands-on advice.

Always remember that safe and responsible reloading is the key to enjoying this rewarding pastime. By taking the time to learn the fundamentals, practicing safe habits, and seeking out reliable resources, you can unlock the full potential of the 300 Blackout.