8.6 mm Blackout

The 8.6mm Blackout is a modern cartridge that has captured the attention of the firearms and reloading community due to its innovative design and unique characteristics. Developed by Q, the company behind the popular .300 Blackout, the 8.6mm Blackout was designed as a solution for those seeking a hard-hitting, versatile, and accurate round that could offer both supersonic and subsonic performance. The cartridge traces its roots back to the .338-caliber family, utilizing the same principles that made .300 Blackout a success: necking up a common case—in this case, the .308 Winchester—to accept larger, heavier bullets. Announced in the early 2020s, the 8.6mm Blackout is also sometimes referred to as 8.6 BLK or 8.6x43. Its development focused on providing optimal performance in short-barreled rifles with fast twist rates, expanding possibilities for hunters, shooters, and suppressor enthusiasts alike.

In practice, the 8.6mm Blackout is incredibly versatile, lending itself well to a variety of applications. For reloaders, the cartridge offers unique performance in both suppressed and unsuppressed configurations, making it suitable for everything from tactical and home defense setups to precision subsonic shooting and hunting. Like its predecessor, .300 Blackout, the 8.6mm Blackout works exceptionally well with suppressed firearms. The heavy-for-caliber bullets and fast twist rates result in immense energy delivery at subsonic speeds, making it an excellent choice for those seeking to maximize terminal performance while keeping noise to an absolute minimum. This has made the cartridge particularly popular among hog hunters and those operating in areas where noise suppression is critical.

When it comes to target species, the 8.6mm Blackout really shines for medium to large game hunting, especially within 300 yards. Its compatibility with large, expanding .338-caliber bullets ensures excellent energy transfer on impact, making it well-suited for hogs, deer, bear, and even elk under the right circumstances. The subsonic option, when paired with expanding or solid projectiles, is especially appealing for game management in populated or noise-restricted areas. The cartridge’s reputation for accuracy and energy retention at practical hunting distances provides reloaders and hunters with the confidence to target heavier-bodied animals without concern for insufficient penetration or expansion.

Bullet weight selection is one of the most appealing aspects of the 8.6mm Blackout for reloaders. Typical bullet weights range from 160 grains for supersonic loads all the way up to 300 grains or more for subsonic applications. Commonly used bullet weights are 210gr, 225gr, 250gr, and 285gr, depending on the desired velocity and application. The cartridge utilizes fast twist barrels—often 1:3 or 1:4 twist—to stabilize these heavy, long projectiles, which in turn increases lethality through greater yaw and expansion on impact. With case capacities optimized for .338 projectiles yet intended for use in AR-10 and bolt-action platforms, 8.6mm Blackout reloaders enjoy a wide range of component options and can easily experiment to tune loads for accuracy, energy, and terminal effect. The compact overall length and efficient powder column add up to reliable cycling and performance, making it a fascinating new choice for advanced reloaders looking to push ballistic boundaries.