The 5.56mm NATO and .300 AAC Blackout (commonly known as 300 Blackout) are two different rifle cartridges with distinct characteristics. Here are the key differences between them:
- Caliber and Size:
- 5.56mm NATO: The 5.56x45mm NATO cartridge is a smaller and lighter round. It has a bullet diameter of approximately 5.56mm (0.223 inches) and an overall length of around 57mm (2.26 inches).
- .300 AAC Blackout: The .300 AAC Blackout cartridge, also known as 7.62x35mm, is a larger and heavier round. It has a bullet diameter of approximately 7.62mm (0.308 inches) and an overall length similar to the 5.56x45mm NATO cartridge.
- Velocity and Ballistics:
- 5.56mm NATO: The 5.56mm round is known for its higher velocity and flatter trajectory. It is often used for longer-range shooting and has good accuracy at extended distances.
- .300 AAC Blackout: The .300 Blackout round is designed for shorter barrels and suppressed firearms. It excels at subsonic speeds, making it a popular choice for suppressed firearms, but it has a shorter effective range and trajectory compared to the 5.56mm round.
- Bullet Weight and Types:
- 5.56mm NATO: Typical 5.56mm rounds have a lighter bullet weight, usually ranging from 55 to 77 grains. They are available in various bullet types, including full metal jacket (FMJ), hollow point (HP), and ballistic tip, among others.
- .300 AAC Blackout: .300 Blackout rounds often feature heavier bullets, with common weights ranging from 110 to 220 grains. This cartridge is designed for versatility and is available in supersonic and subsonic loads.
- Effective Range:
- 5.56mm NATO: The 5.56mm NATO cartridge is generally considered effective out to medium and long ranges, making it suitable for a variety of applications, including military and civilian use.
- .300 AAC Blackout: The .300 Blackout cartridge is more suited for short to medium ranges, particularly when used with shorter barrels or suppressed firearms.
- Compatibility:
- 5.56mm NATO: The 5.56mm round is commonly used in AR-15-style rifles. It’s widely available and has a large user base.
- .300 AAC Blackout: The .300 Blackout cartridge is designed to work with AR-15 platforms without the need for extensive modifications. This makes it a popular choice for those looking to switch between 5.56mm and .300 Blackout without changing the rifle’s upper receiver.
The choice between 5.56mm NATO and .300 AAC Blackout depends on your specific needs and preferences. The 5.56mm offers longer range and flatter trajectory, while the .300 Blackout is better suited for short-range and suppressed applications. Consider factors like the intended use of your rifle and the type of shooting you plan to do when choosing between these two cartridges.