Choose Your Size ⋆ AR15NEWS.COM

The 300 Blackout Barrel has gained popularity for its versatility in hunting, home defense, and suppressed shooting. When it comes to optimizing the cartridge’s performance, barrel length plays a crucial role. This article delves into the advantages and disadvantages of different barrel lengths for the 300 Blackout and where to get them.

The main question you need to ask yourself is whether or not you plan on using a suppressor. If you’re looking for the quietest and best handling setup, one could easily go as short as 7.5″, offered by Faxon Firearms.

How Much Does Barrel Length Affect .300 Blackout Velocity?

Based on our personal experience and research, the 9″ 300 blackout  is the best overall barrel length with or without a suppressor, especially since an 8″ barrel is the minimum warranty barrel length for many suppressor manufacturers.

Best Barrel Length For Suppressed 300 Blackout

For optimal performance with a suppressed 300 Blackout, we recommend a barrel length of 8″-10″.

Attaching a 6″ suppressor to this barrel length results in a total length of 14″ to 16″, which provides optimal muzzle velocity for accurate long-range shots.

For the longer range engagements with a suppressed 300 Blackout, use a 16″ barrel with a suppressor for an average velocity of over 2,630 fps, leading to more effective shots and minimal bullet drop.

10.5″ Blackout Barrel

Best Blackout Length For Home Defense

The .300 Blackout round is an excellent choice for home defense as it combines power and efficiency with lethality when fired from a short-barreled rifle.

Using a short-barreled rifle is ideal for home defense as its compactness makes it easier to maneuver throughout the home. Despite its compact size, a .300 BLK round fired from a short barrel can still hit targets up to 100 yards away.

For optimal home defense with the .300 Blackout, a barrel length of at least 6″ to 8″ is recommended.

Side view of a 7.5″ Blackout Barrel

Best 300 Blackout Length For Hunting

The ideal barrel length when hunting with .300 Blackout is one able to reach long-range targets with sufficient bullet velocity and energy on target for a lethal impact.

Longer lengths offer greater accuracy and velocity, with a maximum length of 16″ for the .300 Blackout. This length ensures complete gunpowder combustion to generate maximum force and stabilizes the bullet for a flatter trajectory and improved accuracy.

Additionally, a 16″ barrel offers a long line of sight for better aim, making it the recommended choice for long-range hunting.

16″ Blackout Barrel

Choosing the right barrel length for the .300 BLK can be hard. 

At 10″, the muzzle velocity has not yet reached its peak. Heavy subsonic ammo in a 10″ barrel may have lower velocities but allows for the use of a suppressor without damaging your hearing. Supersonic ammo out of a 10″ barrel retains rifle caliber velocities but with more significant bullet drop at longer distances.

10.5″ Blackout Barrel

At 16″, muzzle velocities are near their maximum. As a result, heavy-grain subsonic bullets struggle to retain their subsonic terminal performance, while supersonic ammo has increased effective range and reduced bullet drop. The 16″ barrel also provides greater energy upon impact, regardless of ammo type.

16″ Blackout Barrel

The barrel twist rate also impacts performance and should be considered when selecting barrel length and determining the effective range of the .300 Blackout. For example, a 1:8 twist is best for lightweight supersonic rounds, while the 1:7 twist is recommended for heavy subsonic rounds with a suppressor.

There are a few factors to consider when selecting the ideal barrel length for the .300 BLK rifle and determining its effective range.