.50 Beowolf

The .50 Beowulf (12.7x42mmRB) is a 12mm caliber rifle cartridge developed by Bill Alexander of Alexander Arms for use in an AR-15 rifle. The cartridge utilizes a rebated rim, sized to match the rim of the 6.5mm Grendel round. The case body is very similar in dimensions to the .500 S&W Magnum revolver cartridge, being slightly longer and fully tapered for automatic feeding in the weapon. The round is intended to improve stopping power greatly at short- to medium-range as compared to the standard 5.56×45mm NATO round. One of its advertised uses is at vehicle checkpoints, since the heavy bullet's flight path is not easily deflected by auto glass or standard vehicle body panels.