.50 Beowulf

.50 Beowulf
5.56 mm compared to .50 Beowulf cartridges.
Type	Rifle
Place of origin	United States
Production history
Designed	2001
Produced	2001
Specifications
Parent case	.50 Action Express
Case type	Rebated rim, straight
Bullet diameter	.500 in (12.7 mm)
Neck diameter	.525 in (13.3 mm)
Base diameter	.535 in (13.6 mm)
Rim diameter	.445 in (11.3 mm)
Case length	1.65 in (42 mm)
Overall length	2.125 in (54.0 mm)
Primer type	Large pistol magnum
Ballistic performance
Bullet mass/type Velocity Energy 300 gr (19 g) Speer Gold Dot JHP Alexander Arms 1,870 ft/s (570 m/s) 2,330 ft·lbf (3,160 J) 325 gr (21 g) Speer JHP Alexander Arms 1,800 ft/s (550 m/s) 2,338 ft·lbf (3,170 J) 335 gr (22 g) Rainer Plated FP Alexander Arms 1,771 ft/s (540 m/s) 2,333 ft·lbf (3,163 J) 335 gr (22 g) Rainier Plated HP Alexander Arms 1,900 ft/s (580 m/s) 2,678 ft·lbf (3,631 J) 400 gr (26 g) Hawk JFP Alexander Arms 1,800 ft/s (550 m/s) 2,878 ft·lbf (3,902 J)
Test barrel length: 16 Source(s): [1]

The .50 Beowulf is a rifle cartridge developed by Bill Alexander of Alexander Arms for use in a modified AR-15 rifle.

The cartridge utilizes a rebated rim, sized to match the rim of the 7.62×39mm and 6.5mm Grendel rounds. 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.

With normal bullet weights between 300 and 400 grains (19 and 26 g), 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 modern lever-action rifles such as the Marlin Model 1895. Adaptability is limited due to its use of the 7.62×39mm bolt face.

The .50 Beowulf is a caliber developed as a specialized cartridge and weapon. Alexander Arms 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.