5.56 vs. 300 Blackout: A Guide to Choosing the Right Cartridge

When deciding between the 5.56 and 300 BLK cartridges, understanding their unique characteristics, benefits, and practical applications is essential. Both rounds have their strengths and are tailored to different scenarios, making them popular choices for hunters, sport shooters, and gun enthusiasts. This detailed comparison will provide you with the historical context, performance metrics, and specific uses of each cartridge to help you make an informed decision.

Historical Background

5.56

Development: The 5.56x45mm cartridge was developed in the late 1950s as part of the U.S. military’s shift to lighter, high velocity ammunition. It was designed to replace the heavier 7.62x51mm round, offering a lighter option with reduced recoil while still providing effective range and firepower.

Adoption: Officially adopted by NATO forces in the early 1960s, the 5.56 became the standard ammunition for the M16 rifle, widely used by the U.S. military and its allies. It was standardized under NATO’s STANAG 4172 agreement in 1980, solidifying its role in military use.

Evolution: The 5.56 is derived from the .223 Remington cartridge, developed by Remington Arms in the early 1960s. Over the years, it has seen several enhancements, including the SS109 and M855A1 variants, which offer improved performance and penetration, particularly against light barriers.

300 BLK

Origins: The 300 AAC Blackout (7.62x35mm) was developed by Advanced Armament Corporation (AAC) in 2010 to address some of the limitations of the 5.56, particularly its performance in short barreled rifles and subsonic configurations. Its design enables effective performance in compact firearms, making it a versatile option for a variety of shooting applications.

Design Goals: The primary goal behind the 300 BLK was to create a cartridge that could be used with both supersonic and subsonic loads, providing strong performance with or without a suppressor. Importantly, it was designed to be compatible with standard 5.56 magazines and components, with only the barrel needing to be changed.

Adoption: Approved by the Sporting Arms and Ammunition Manufacturers' Institute (SAAMI) in 2011, the 300 BLK has gained popularity for its adaptability and effectiveness in various scenarios. Its ability to transition between high-velocity and subsonic rounds has made it a popular choice for hunting, sport shooting, and home defense.

Uses and Applications

5.56

• Hunting: The 5.56 is suitable for hunting small to medium game, such as varmints and deer, particularly in open areas where precision and range are important.
• Target Shooting: Its accuracy, low recoil, and affordability make the 5.56 a popular choice among recreational shooters and those participating in competitive shooting sports.
• Home Defense: The 5.56 offers manageable recoil and effective performance at typical home-defense distances, though over-penetration can be a concern.

300 BLK

• Hunting: The 300 BLK is highly effective for hunting medium-sized game like deer and hogs, particularly in wooded or brush filled areas. Supersonic loads deliver strong terminal performance, while subsonic loads offer quieter operation.
• Suppressed Shooting: With subsonic ammunition, the 300 BLK is exceptionally quiet when paired with a suppressor, making it ideal for reducing noise during shooting. This is especially useful in environments where discretion is valued, such as hunting near populated areas.
• Home Defense: The 300 BLK provides greater stopping power at close ranges, and subsonic loads offer reduced risk of over-penetration, making it a versatile option for home defense.

Ballistics and Performance

5.56

• Velocity: The 5.56 delivers high velocity, typically around 3,000 feet per second (fps), resulting in a flat trajectory and effective range out to several hundred yards.
• Recoil: Low recoil makes the 5.56 easier to control, allowing for quick and accurate follow up shots.
• Penetration: Known for good penetration, the 5.56 can sometimes over-penetrate in certain scenarios, which may be a consideration depending on the intended use.

300 BLK

• Velocity: The 300 BLK, with supersonic loads, reaches velocities between 1,900 and 2,400 fps. While slower than the 5.56, it delivers more energy at shorter ranges, making it highly effective for close to medium distances.
• Recoil: The recoil is slightly higher than the 5.56 but remains manageable, making it suitable for a range of shooters.
• Penetration: Supersonic 300 BLK rounds offer substantial penetration and stopping power, while subsonic rounds provide controlled penetration, reducing the risk of over penetration in close quarters.

Compatibility and Versatility

5.56

• Platform: The 5.56 is compatible with a wide variety of AR-15 platforms and other rifles, making it a flexible choice for shooters who want to switch between different setups.
• Availability: Due to its widespread use, the 5.56 is widely available and generally more affordable than the 300 BLK, particularly when buying in bulk.

300 BLK

• Platform: Designed to work with AR-15 platforms, the 300 BLK only requires a barrel change to switch from 5.56, allowing for a simple and cost-effective caliber swap.
• Versatility: The ability to use both supersonic and subsonic loads provides unique flexibility, whether for hunting, target shooting, or self defense. This versatility makes it an attractive choice for those seeking a do it all cartridge.

Final Thoughts

Choosing between the 5.56 and 300 BLK ultimately comes down to your specific needs and preferences. The 5.56 excels in range, affordability, and ease of control, making it a great all-around choice for hunting, target shooting, and home defense. On the other hand, the 300 BLK shines in scenarios requiring compact rifles, suppressed shooting, and greater stopping power at shorter ranges.

Both cartridges have proven themselves capable in a variety of roles. Whether you prioritize range and cost or versatility and close-range performance, understanding their unique characteristics will help you select the best option for your shooting needs.

Product Recommendations

For those interested in purchasing these cartridges or related components, here are some recommended products from The Freedom Warehouse:

5.56 NATO:

• BCM Blem upper Receiver 5.56 NATO 11.5" 1:7 Twist Carbine Length
• BCM Blem Upper Receiver 13.9" 5.56 NATO Mid Length
• BCM Blem Upper Receiver 16" 5.56 NATO Mid Length

300 Blackout:

• BCM Blem Upper Receiver 300 Blackout 9" 1:7 Twist Pistol length
• BCM Blem Upper Receiver 300 Blackout 8" 1:7 Twist Pistol length
• BCM Blem Upper Receiver 300 Blackout 7" 1:7 Twist Pistol length
• BCM Blem Upper Receiver 300 Blackout 6" 1:7 Twist Pistol length