50 Beowulf Ammo is a 12mm caliber rifle cartridge developed by Bill Alexander of Alexander Arms for use in an AR-15 rifle
The .50 Beowulf is a proprietary caliber developed as a specialized cartridge. Alexander Arms and Delta Firearms oversees all aspects of the production of the system and related accessories. Their reluctance to divulge information has been a source of irritation to some writers. Because Alexander Arms holds a trademark on the name .50 Bw, a number of other companies produce weapons and ammunition reverse engineered to the same dimensions under the name 12.7x42mm.
Although much has been written about its tactical uses, the .50 BW is gaining recognition as a sporting cartridge. It is becoming more widely recognized as being usable for a wide variety of North American game, including deer, moose, and black bear