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Date Posted: June 24, 2011
AAC 300 Blackout Cartridge
John Kraft
AAC brings a wildcat concept into the mainstream

The AR-15/M-16 and the .223 Remington/5.56 NATO round were born together in the 60s, and controversy has followed the two around ever since.  While the M-16 family has undergone many, many improvements and evolutions over the years to become the war fighting weapon of choice for western armies, the .223 Remington/5.56 has always been limited by its dimensions. 

There have been many attempts to fix the supposed shortcomings of 5.56 NATO rounds, from using heavy grain match ammunition (77 gr Sierra Match King, in issued MK 262 Mod 1 ammo) to all copper or bonded projectiles with great penetration ability.  One of the more unique approaches though, was the “300 Whisper” solution of squeezing a 7.62mm projectile into a cut down .223 Remington or .221 Fireball case. The 300 Whisper never found widespread commercial appeal as it remained a “wildcat cartridge”, ie, a cartridge which does not have standardized specifications from SAAMI

Advanced Armament Corporation, a company made famous for its silencers and risque marketing (if you consider attractive and tattooed young ladies to be risque) took the 300 Whisper concept, and developed its own cartridge and specifications to be submitted to SAAMI.  This new cartridge became the AAC Blackout (300 BLK), and due to its submittal to SAAMI, anyone and everyone can produce barrel and ammunition for this caliber.

The 300 BLK is notable in that it makes and excellent platform for a suppressed weapon.  While 5.56 subsonic loadings are notoriously finicky, it is easy to create reliably functioning sub sonic rounds for 300 BLK which also suppress extremely well due to low amounts of expanding gas.  Sub-sonic 300 BLK rounds not only work extremely well with silencers, they also carry about as much muzzle energy as .45 ACP.  AAC developed a silencer to work specifically with the 300 Blackout (the 762-SDN6 which looks like a beefed up M4-2000), though the 300 BLK can work with 9mm suppressors with the right attachment.

Full power 300 BLK rounds mimic the external ballistics of 7.62*39 (the round used in AK-47 pattern rifles) and have more muzzle energy than both typical AK or M-16/M4 rounds.  Ballistic gel testing of various projectiles at full power loadings for 300 BLK showed penetration of 12 to 21 inches, averaging around 18 inches of penetration.  The 300 BLK's typical penetration capability is well beyond FBI recommended 12" of penetration in ballistic gel.

With SAAMI specifications, the ammunition and parts manufacturers are free to produce 300 BLK rounds and parts as they please.  With the full backing of AAC's parent company, Remington Arms, the 300 BLK looks poised to become a staple cartridge in the future given its excellent characteristics both with, and without sound suppressors.

300 Blackout, (300 BLK) pros

  • Just barrels need to swapped out in existing AR-15 rifles to shoot 300 BLK:  Backward compatibility with the same magazines, bolts, etc.
  • SAAMI specifications means lots of manufacturers are producing parts and ammo, keeping prices low!
  • Excellent sub sonic loadings for use with sound suppressors.
  • Full power loadings mimic the powerful 7.62*39 round.

West Coast Armory is expecting a large shipment of ammunition and barrels in to our Bellevue pro-shop and Issaquah retail location to suit your needs.  Given that silencer use legalization is looking very likely in the near future, the 300 BLK is an excellent cartridge one should consider for a rifle build!

4/16/2011 updated:  Have a good amount of subsonic 300 BLK in stock!




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