The .300 AAC Blackout, also known as 7.62×35mm, is an intermediate cartridge developed in the United States by Advanced Armament Corporation (AAC) for use in the M4 carbine. The cartridge yields increased performance in shorter barrels and effective subsonic performance for silencer use when compared to 5.56mm NATO. The .300 AAC Blackout uses standard 5.56mm NATO magazines and components with the exception of the barrel.
The .300 AAC Blackout plastic tipped, left, compared to .300 AAC Blackout 125 gr match, .300 AAC Blackout 220 gr subsonic, 5.56×45mm NATO, and 7.62×39mm.
.300 AAC Blackout rounds shot from a suppressed M4 carbine
Example of a .300 AAC Blackout shot in a block of gel
AR-15 rifle with dustcover and magazine band that identify it as having a chambering of .300 AAC Blackout
An intermediate cartridge is a rifle/carbine cartridge that has significantly greater power than a pistol cartridge but still has a reduced muzzle energy compared to fully powered cartridges, and therefore is regarded as being "intermediate" between traditional rifle and handgun cartridges.
From left to right: 9×19mm (pistol cartridge) 7.92×33mm (intermediate cartridge) 7.92×57mm (fully powered cartridge)
The Sturmgewehr 44, a development of the earlier Maschinenkarabiner 42(H)
The 10.4x38mmR Swiss is an early example of an Intermediate cartridge.
