MPN: 0010120007


  • Precision CNC machined to match grade tolerances for extreme accuracy
  • Chambered in 300 Blackout
  • Non-glare bead blasted stainless steel then Armor Black coated for longevity and ease of maintenance
  • 5R Button Rifling with 1:7 twist rate

*A barrel that is shorter than 16" is only for use on a pistol configuration firearm or a NFA registered Short-Barreled Rifle (SBR). All NFA laws apply!


  • Caliber: .300 Blackout
  • Length: 10.5"
  • Gas Placement: Pistol-Length
  • Gas Seat: 0.750"
  • Twist Rate: 1:7 5R Button Rifling
  • Weight: 1 lb. 4.7 oz.
  • Material: Stainless Steel
  • M4 Feed Ramps: Yes
  • Muzzle Thread Pattern: 5/8"-24
  • Finish: Non-glare bead blasted then Armor Black coated


  • AR-15


If you’re looking to build an AR pistol or a short-barreled rifle (SBR), you will find the Seekins Precision 10.5" 300 Blackout barrel to be the perfect piece for your firearm. Whether you’re choosing replacement barrel or building an AR from scratch, this match-grade barrel is certain to meet your need for durability and accuracy.

Match Grade 10" .300 Blackout Barrel by Seekins Precision

When you bring an upgrade as serious as a match grade barrel into your life it bears some consideration. I know, even a safety selector is important, but a high-end barrel is much more so. When you take a closer look at a Seekins Precision 300 blackout barrel, you will find custom touches usually found on much higher priced barrels. Seekins chose to use 1:7 5R button rifling in your new 10.5 inch 300 blackout barrel for a good reason. First, a 1:7 twist is the optimum rate of twist for heavier bullets fired from shorter barrels. This is perfect for a .300 blackout because it loves the heavier ammunition.

The 5R designation stands for the five ridges incorporated in the barrels' rifling. It may sound like a small thing, however, it is not. The use of five ridges instead of the standard six means that no area of the bullet is compressed on its direct opposite side. This more concentric design results in less bullet deformity, therefore, a more spherical and accurate bullet.

Why Seekins Precision 300 Blackout Barrel?

All Seekins Precision products live up to the company’s name. The 10.5" 300 Blackout barrel is precision CNC-machined from one of the finest stainless steel blanks available. The bead-blasted finish helps prevent the risk of glare from the sun or other light sources. Seekins cut M4 feed ramps into their 416 stainless steel 10.5 inch 300 blackout barrel to ensure better feeding. Additionally, the .300 blackout round itself is a wonderful choice for this set-up. It was originally developed from the .300 whisper round and excels where other rounds fall short. The Seekins Precision 300 blackout barrel delivers sub-sonic rounds from a suppressed barrel that are about the quietest you can get.

Seekins takes quality very seriously. Before each barrel is released for purchase, it is given four inspections to ensure perfect concentricity and alignment. With a commitment such as this, you can feel confident that the barrel you hold in your hands has the maximum potential for accuracy. Every Seekins barrel is threaded to fit compatible muzzle devices. This 300 Blackout barrel is compatible with any Mil-Spec upper receiver and is the preferred choice for suppressed AR systems. The AR-15 300 Blackout barrel also features the exclusive Seekins gas block alignment dimple to facilitate a quick and easy installation of any .750” gas block. Order your barrel today and experience the quality of Seekins Precision.

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