.300 Blackout

The .300 AAC Blackout (designated as the 300 BLK by the SAAMI and 300 AAC Blackout by the C.I.P.), also known as 7.62×35mm is a carbine cartridge developed in the United States by ADVANCED ARMANENT CORPORATION (AAC) for use in the M4 carbine. Its purpose is to achieve ballistics similar to the 7.62x39mm Soviet cartridge in anAR-15while using standard AR-15 magazines at their normal capacity. It can be seen as a SAAMI-certified copy of J. D. Jones' wildcat.300 Whisper. Care should be taken not to use 300 BLK ammunition in a rifle chambered for .223/5.56