8.6 mm Blackout Load Data

Caliber Overview

The 8.6mm Blackout is a relatively new cartridge that has garnered significant interest among firearm enthusiasts and ammunition reloaders. Designed and introduced by Q, LLC, particularly spearheaded by renowned firearm innovator Kevin Brittingham, the 8.6mm Blackout was created to offer enhanced capability over existing rounds, including the widely popular .300 Blackout. The concept for the 8.6mm Blackout emerged around 2020, drawing inspiration from the successful adaptation of .300 AAC Blackout—which itself was a modification of the .223/5.56×45mm case. The goal for 8.6mm Blackout was to deliver superior energy, increased terminal ballistics, higher subsonic performance, and reliable cycling in a suppressed AR-10 platform. This cartridge is based on a shortened and necked-down .338 Lapua Magnum case, brought down to accept 8.6mm (.338 caliber) bullets, thus combining heavy projectiles with a compact design and exceptional accuracy potential, especially with fast twist barrels.

The 8.6mm Blackout is intended for a wide spectrum of applications, making it an attractive choice for reloaders who value versatility. One of the principal uses is within the sporting and hunting sectors, where both supersonic and subsonic loadings can be tailored for medium and large game at moderate ranges. The cartridge’s compatibility with AR-10 platforms, as well as bolt-action rifles, means it can readily serve in either semi-automatic or precision rifle roles. Its appeal is further heightened for shooters who operate with suppressors: the heavy bullets and subsonic loads combine to offer very quiet, effective performance in tactical, personal defense, and hunting applications. Additionally, the 8.6mm Blackout is becoming increasingly popular for target shooters and competitive marksmen seeking a modern, hard-hitting cartridge with reduced recoil compared to other .338 caliber options.

Target species for the 8.6mm Blackout include a variety of game animals that require deep penetration and substantial energy transfer at short to moderate distances. Whitetail deer, feral hogs, black bear, and even elk fall within the practical spectrum for ethical harvest when using appropriate bullet selections. Subsonic loads, in particular, shine in regions with dense cover or when minimal noise signature is required, such as in wildlife management or population control scenarios. The ability to use both expanding and solid projectiles enables reloaders to further fine-tune their ammunition for optimal performance on specific species, ensuring quick, humane takedowns.

Typical bullet weights for the 8.6mm Blackout range widely, from approximately 160 grains in lighter, supersonic offerings, up to a hefty 338 grains designed for subsonic use. The most notable characteristic of this caliber is its exceptionally fast barrel twist rate, often as aggressive as 1:3". This fast twist is engineered to stabilize long, heavy projectiles—especially those fired at subsonic velocities—thereby maintaining accuracy and maximizing terminal effect. The overall case length is shorter than the parent .338 Lapua Magnum, enabling it to fit comfortably in standard .308 Winchester/7.62 NATO-length magazines. Reloaders will also appreciate the cartridge’s relatively moderate pressures, which combine with efficient powder usage and manageable recoil. This unique blend of traits gives those who handload ample opportunities to experiment with a wide range of bullet weights, seating depths, and powder types tailored for their shooting or hunting requirements. The 8.6mm Blackout stands out as a modern, innovative caliber that rewards skillful reloading with exceptional performance and versatility.