The .50 Beowulf (12.7x42mmRB) is a 12mm caliber

rifle cartridge A rifle cartridge is a firearm cartridge (firearms), cartridge primarily designed and intended for use in a rifle/carbine, or machine gun. Types Full-powered A full-powered cartridge is a rifle cartridge used interchangeably between servic ...

developed by Bill Alexander of Alexander Arms for use in an AR-15 rifle.

Design and specifications

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 A revolver is a repeating handgun with at least one barrel and a revolving cylinder containing multiple chambers (each holding a single cartridge) for firing. Because most revolver models hold six cartridges before needing to be reloaded, ...

cartridge, being slightly longer and fully tapered for automatic feeding in the weapon. The round is intended to improve

stopping power Stopping power is the supposed ability of a weapon – typically a ranged weapon such as a firearm – to cause a target (human or animal) to be incapacitated or immobilized. Stopping power contrasts with lethality in that it pertains only to a ...

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.

Design limitations

With normal bullet weights between , overall cartridge length shorter than that of an AR-15 magazine well, and holding to pressures of 33,000 psi limited by the AR bolt strength system, the .50 Beowulf is best described as a low-velocity, heavy caliber, making its ballistics roughly equivalent to those of early .45-70 Government rounds rather than the higher pressure rounds tolerated by lever-action rifles such as the Marlin Model 1895.

Proprietary status

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 Beowulf, a number of other companies produce weapons and ammunition reverse-engineered to the same dimensions under the name 12.7x42mm.

Sporting uses

Although much has been written about its tactical uses, the .50 Beowulf 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.

Similar cartridges

The cartridge has its lineage in the .50 Action Express, starting with the L.A.R. Grizzly and in modern times, the Magnum Research

Desert Eagle The Desert Eagle is a trigger (firearms), single-action, Gas-operated reloading, gas-operated, semi-automatic pistol capable of chambering the .50 Action Express, the largest centerfire cartridge of any magazine-fed, self-loading pistol and a nu ...

pistol, with significant modification to improve functionality and safety in the AR-15 rifle.

Notes

External links

.50 Beowulf General Technical Specifications
on the Alexander Arms website

Jeff Quinn, ''Gunblast.com'' (online magazine), July 8, 2002

Jeff Quinn, ''Gunblast.com'' (online magazine), June 15, 2003

Anthony G. Williams, ''The Cartridge Researcher, the bulletin of the European Cartridge Research Association'', May 2005

Jeff Quinn, ''Gunblast.com'' (online magazine), March 12, 2004 {{Rebated rim cartridges 12.7 mm firearms Rebated rim cartridges Paramilitary cartridges Pistol and rifle cartridges