[1] The .500 Jeffery was introduced to bring firepower comparable to the .505 Gibbs into a standard-sized 1898 Mauser action as used with the 8x57mm and 7x57mm cartridges.
When introduced, the .500 Jeffery was technically rated as the most powerful rifle cartridge although in reality not quite up to .505 Gibbs' performance.
Like the .505 Gibbs, the .500 Jeffery is enjoying somewhat of a renaissance among American shooters and African big game hunters in the early 21st century, almost 100 years after its introduction.
The original Jeffery uses a single-column two-shot magazine to get around the potential reliability problems resulting from a rebated rim.
When the .500 Jeffery was first introduced it was loaded to a velocity of 2,350 feet per second (720 m/s) topped off with a 535-grain bullet generating 6,560 ft⋅lbf (8,890 J) of muzzle energy, which made it a pretty good hunting caliber for thick-skinned dangerous game.