Introducing the Advanced Armament Corp. 300 AAC Blackout (300BLK). This system was developed to launch 30 caliber projectiles from the AR platform without a reduction in magazine capacity and compatible with the standard bolt.
Full power 115-125 grain ammunition matches the ballistics of the 7.62x39mm AK, and eclipses 5.56mm with much higher-mass projectiles for a more dramatic effect on the target. Or choose subsonic cartridges for optimal use with a sound suppressor - 220 grain Sierra OTM (open-tip match) bullets vastly outperforms a 9mm MP5-SD in penetration and long range accuracy.
Ammo and brass prices are low - Remington 115 grain UMC ammo is $12.99 a box MSRP - and it is not bare bones. It has waterproofed primers, crimped and cannelured open-tip match bullets, and a low-drag design.
At 300 meters, 300 BLK has 16.7% more energy than 7.62x39mm. Max effective range, using M4 military standards for hit probability, is 440 meters for a 9 inch barrel, and 460 meters for a 16 inch barrel. 300 BLK from a 9 inch barrel has the same energy at the muzzle as a 14.5 inch barrel M4, and about 5% more energy at 440 meters - even though the barrel is much shorter.