The 8.6 Blackout is a modern .338-caliber centerfire cartridge introduced around 2021, designed for heavy subsonic bullets and excellent suppressed performance, often paired with fast-twist barrels. Conceptually a larger counterpart to the 300 Blackout, it targets suppressed shooting and moderate-range hunting.

The 8.6 Blackout was introduced around 2021 as a larger-bore companion concept to the popular 300 Blackout, designed around heavy .338-caliber bullets and a strong focus on suppressed shooting. A distinctive design element is its use of a very fast barrel twist rate, intended to stabilize heavy subsonic bullets and produce specific terminal behavior, which became a notable talking point of the cartridge. Ballistically the 8.6 Blackout is built to excel with heavy subsonic loads that pair extremely well with suppressors for quiet shooting, while also offering supersonic loads for hunting and general use. It delivers larger-bore .338 performance at short-to-moderate range, oriented toward the suppressed and hunting roles where that combination is valued, and it is designed to function in appropriately built short-action and AR-platform rifles. As a newer cartridge, its rifle and ammunition selection is at an earlier stage relative to established rounds, though it attracted considerable interest in the suppressor and hunting communities for its heavy-bullet subsonic focus. Today the 8.6 Blackout is used for suppressed shooting, moderate-range hunting, and recreational use, with a growing base of support. Its pairing of heavy .338-caliber subsonic capability with a fast-twist, suppressor-oriented design is what distinguishes it among modern specialty cartridges.

General information about this caliber — not a recommendation for this specific firearm.