8.6mm Blackout (8.6×43 mm), sometimes referred to as 8.6 BLK, is a centerfire rifle cartridge developed by the firearms manufacturer Q, LLC. It utilizes a shortened case from the 6.5mm Creedmoor necked up to an 8.6 mm caliber (8.585 mm or 0.338 in diameter) projectile. 8.6 Blackout is designed for use in bolt-action rifles or as a caliber conversion for AR-10 style rifles.
The only required modification to convert an existing .308 Winchester-chambered rifle to 8.6mm Blackout is the replacement of the barrel. The 8.6 Blackout shares the same case head and bolt diameter as its parent cartridge, 6.5mm Creedmoor. All other components of a standard AR-10 rifle are compatible. Modifications to the operating system such as the buffer, buffer spring and gas system may be made in order to optimize functionality of the firearm. 8.6 Blackout fits in standard, unmodified .308 Winchester or 6.5 Creedmoor magazines with no effect on capacity.
The 8.6 Blackout is designed for barrels using a 76 mm or 102 mm (1:3 in or 1:4 in) twist rate and bullet weights between for supersonic loads and for subsonic loads. The "fast" twist rate 8.6mm Blackout was intended to create better expansion and more terminal energy transferred to the target through the "blender effect" of a rapidly-spinning subsonic bullet.
Platforms +ManufacturerModelTypeCountryQFixBolt action rifleUnited StatesQBoomboxSemi-automatic rifleUnited StatesChattahoochee MunitionsCM7S Bolt action rifle and pistolUnited StatesChattahoochee MunitionsCM10 Semi-automatic rifle and pistolUnited StatesFaxon FirearmsSentinelSemi-automatic rifleUnited StatesGorilla AmmunitionGF-10Semi-automatic rifleUnited StatesBear Creek ArsenalBC-10 Semi-automatic rifleUnited StatesRossiLWCSingle shot rifleUnited StatesRobinson ArmamentXCR-M (Mini & Mid)https://robinsonarmament.com/products/Semi-automatic rifleUnited States
See also 9×39mm .300 AAC Blackout .338 Whisper .338 Federal 6.5mm Creedmoor .30 Thompson Center
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