Choosing the right ammunition for your firearm is crucial for both performance and safety. Among the popular options available, 300 AAC Blackout and 5.56 NATO stand out as two highly favored rounds among shooters. Each has a distinct characteristics, and understanding their differences can help you make an informed decision for your shooting needs.

In this post we’ll explore the features of both types of ammo, their compatible firearms, scenarios where one may be over the other and how AimHi Family Firearms Center can help you in your next ammunition purchase.

Characteristics of 300 AAC Blackout

300 AAC Blackout

The 300 AAC Blackout, also known as the 300 BLK, was developed by Advanced Armament Corporation (AAC) to deliver improved performance in shorter barrels, especially with suppressors. It offers versatility for both subsonic and supersonic applications.

Key Features

  • Bullet Weight: Typically ranges from 110 to 220 grains.
  • Velocity: Subsonic rounds travel approximately 1,000 feet per second.
  • Effective Range: Optimal performance up to 300 yards.
  • Recoil: Generally moderate, depending on the load.

Compatible Firearms

  • AR-15 Platforms: With a simple barrel change, an AR-15 chambered in 5.56 NATO can be converted to fire 300 BLK.
  • Bolt-Action Rifles: Many manufacturers offer bolt-action models designed for 300 BLK.
  • Suppressors: Ideal for use with suppressors due to its subsonic capabilities.

Characteristics of 5.56 NATO

The 5.56 NATO, or 5.56x45mm, is the standard issue round for NATO forces and has a long military history of military and civilian use. Known for its high velocity and flat trajectory, it’s a staple for tactical and defensive shooting.

Key Features

  • Bullet Weight: Typically ranges from 55 to 77 grains.
  • Velocity: Usually exceeds 3,000 feet per second.
  • Effective Range: Optimal performance up to 500 yards or more.
  • Recoil: Generally light, making it easier to control.

Compatible Firearms

  • AR-15 Platforms: The standard caliber for AR-15 rifles.
  • Military and Law Enforcement Rifles: Commonly used in various tactical rifles.
  • Bolt-Action Rifles: Available in several precision models.

When to Choose 300 AAC Blackout or 5.56 NATO

Home Defense

  • 300 AAC Blackout: Preferred for home defense due to its superior performance in shorter barrels and subsonic rounds, which are quieter and reduce the risk of over-penetration.
  • 5.56 NATO: Effective but may produce more noise and potentially over-penetrate in indoor settings.


  • 300 AAC Blackout: Suitable for hunting medium-sized game such as deer, especially at shorter ranges. Its heavier bullet can deliver more energy upon impact.
  • 5.56 NATO: Better for small game and varmints. Its higher velocity provides a flatter trajectory, making it easier to hit smaller targets at longer ranges.

Tactical and Defensive Use

  • 300 AAC Blackout: Ideal for close-quarters engagements due to its efficient performance in shorter barrels and the ability to use suppressors effectively.
  • 5.56 NATO: Favored for longer-range engagements and scenarios requiring higher magazine capacities and lighter recoil for faster follow-up shots.

Range Shooting and Training

  • 300 AAC Blackout: Offers versatility with both subsonic and supersonic loads, providing a varied shooting experience.
  • 5.56 NATO: Generally more cost-effective and widely available, making it a practical choice for frequent training sessions.

How AimHi Can Help

At AimHi Family Firearms Center, we understand choosing the right ammunition can be overwhelming. That’s why our knowledgeable staff is here to help. Whether you’re seasoned shooter or new to firearms, we offer personalized recommendations to match your specific needs and preferences.

Visit our online store or physical shop today and explore our selection of 300 AAC Blackout and 5.56 NATO options. We carry top brands and ensure all our products meet the highest standards of quality and performance. Our experienced team is always available to provide guidance on ammunition selection, compatible firearms and shooting techniques!