The .500 A-Square is a belted, bottleneck rifle cartridge

Cartridge (firearms)

A cartridge, also called a round, packages the bullet, gunpowder and primer into a single metallic case precisely made to fit the firing chamber of a firearm. The primer is a small charge of impact-sensitive chemical that may be located at the center of the case head or at its rim . Electrically...

, developed by Col. Arthur B. Alphin in 1976. The cartridge is based on the .460 Weatherby Magnum

.460 Weatherby Magnum

The .460 Weatherby Magnum is a belted, bottlenecked rifle cartridge, developed by Roy Weatherby in 1957. The cartridge is based on the .378 Weatherby Magnum necked up to accept the bullet. The original .378 Weatherby Magnum parent case was inspired by the .416 Rigby...

 necked up to accept the .510 in (13.0 mm) bullet; the same as the .50 BMG

.50 BMG

The .50 Browning Machine Gun or 12.7×99mm NATO is a cartridge developed for the Browning .50 caliber machine gun in the late 1910s. Entering service officially in 1921, the round is based on a greatly scaled-up .30-06 cartridge...

 cartridge. This was Col. Alphin's first commercial sporting cartridge and was designed in “response to some sever problems experienced with the .458 Winchester

.458 Winchester Magnum

The .458 Winchester Magnum is a belted, straight-taper cased, dangerous game rifle cartridge. It was introduced commercially in 1956 by Winchester and first chambered in the Winchester Model 70 African rifle. It was designed to compete against the .450 Nitro Express and the .470 Nitro Express...

 on safari

Safari

A safari is an overland journey, usually a trip by tourists to Africa. Traditionally, the term is used for a big-game hunt, but today the term often refers to a trip taken not for the purposes of hunting, but to observe and photograph animals and other wildlife.-Etymology:Entering the English...

 in Mozambique

Mozambique

Mozambique, officially the Republic of Mozambique , is a country in southeastern Africa bordered by the Indian Ocean to the east, Tanzania to the north, Malawi and Zambia to the northwest, Zimbabwe to the west and Swaziland and South Africa to the southwest...

.”

The .500 A-Square is a proprietary cartridge and the world's most powerful commercially available “sporting” cartridge. However, the .50 BMG is the world's most powerful commercial cartridge for any shooting purpose. The .500 A-Square is use specifically as an African, thick skin, dangerous game, rifle cartridge for the hunting of Elephant

Elephant

Elephants are large land mammals in two extant genera of the family Elephantidae: Elephas and Loxodonta, with the third genus Mammuthus extinct...

s and Cape Buffalo as well as a back up gun for professional hunters and guides.

Overview

The .500 A-Square cartridge is commercially available from both A-Square and Midway USA as loaded ammunition. The ammunition comes in three loads: 600 grains (38.9 g) Monolithic Solid; 600 grains (38.9 g) soft nose thick jacket and 600 gr (38.9 g) soft nose thin jacket. All bullet/cartridge combination are advertised with a muzzle velocity of 2470 ft/sec (753 m/s) and muzzle energy of 8127 ft-lbf (11019 J).

In comparison the parent cartridge, the .460 Weatherby Magnum as commercial loaded with 500 gr (32.4 g) Monolithic Solid has a muzzle velocity of 2580 ft/sec (786 m/s) and muzzle energy of 7389 ft-lbf (10018 J). The .50 BMG as commercial loaded with 661 gr (42.8 g) FMJ M33 ball ammo has a muzzle velocity of 2750 ft/sec (838 m/s) and muzzle energy of 11102 ft-lbf (15052 J).

Although there is limited hand-loading information, bullet weights (hunting) are from between 300 gr (19.4) to 647 gr (41.9). All reloading components and equipment are available for the .500 A-Square. Loaded ammunition costs about $9.50 USD (2010) per round.