|Place of origin||England|
|Case type||Rimless, Bottleneck|
|Bullet diameter||.510 in (13.0 mm)|
Test barrel length: 24"|
Source(s): Norma Ammunition RealGuns reloading data
The .500 Jeffery is a big-game rifle cartridge that first appeared around 1920, and was originally introduced by the August Schuler Company, a German firm, under the European designation "12,7x70 mm Schuler" or ".500 Schuler". When offered by the famed British outfitter Jeffery's Guns, Rifles [sic], it was renamed the .500 Jeffery so as to be more palatable to British hunters and sportsmen following World War One.
When introduced the .500 Jeffery was the most powerful rifle cartridge in existence and remained so prior to World War II. The 505 Gibbs introduced prior to the .500 Jeffery (1911) has only recently been loaded to higher modern pressures although still below that of the .500 Jeffery and hence remains less powerful.
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 their introduction. As of 2009, Norma, Kynoch, Mauser, Corbon, and Westley Richards are offering loaded ammunition in 500 Jeffery. There may be other manufacturers as well. Ammunition can cost anywhere from $150 for a box of 20 or more depending on the manufacturer.
There have been a few rifles chambered in the 500 Jeffery including Jeffery, Heym, CZ-USA, and a few single shots including Ruger no1, and the Butch Searcy & Co.. Mauser offers its Model 98 magnum in the caliber. Its "Elephant" model is offered in 500 Jeffery exclusively. In 2011, Sako began offering the caliber in its Model 85 "Safari" rifle using a new XL size action.
The 500 Jeffery has had a few issues since its introduction. It has a rather short neck length that can make it difficult to seat bullets with a large sectional density. Also it has a small shoulder. This is not usually an issue but since the 500 Jeffery also has a rebated rim, it makes it rather difficult to extract in extreme conditions.
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 makes it a pretty good hunting caliber generally where thick skinned dangerous game occurs. Since then reloading capabilities have advanced being able to launch heavier bullets at higher velocities. Now with modern reloads the 500 Jeffery can launch a 600 grain bullet at a muzzle velocity ranging at about 2,450 to 2,500 ft/s (750 to 760 m/s). max. generating 7,995 ft·lbf (10,840 J) to 8,100 ft·lbf (11,000 J) With newer reloads it made the 500 Jeffery the most powerful production cartridge in the world until the introduction of the .460 Weatherby Magnum. With reloads the 460 weatherby can reach levels of power of about 8,300 ft·lbf (11,300 J) of muzzle energy. Also the .600 Nitro Express exceeds the 500 Jeffery in muzzle energy with 120 grains of cordite. No doubt the 500 Jeffery is still a respected caliber all across the world.
History is silent as to the "design concept" behind this caliber. However, it seems safe to assume that it was intended to be just about the most powerful caliber that could be handled by a full size man who had experience shooting heavy rifles. Indeed, the less powerful 505 Gibbs and 500 Nitro Express were considered to be heavier than most men could handle. In light of this, modern, high pressure handloads that drive the muzzle energy to over 7,000, even 8,000-foot (2,400 m) pounds would seem to push this caliber over the top and render it unusable. A 535 grain bullet with a muzzle velocity of 2300 to 2,400 ft/s (730 m/s) should be more than adequate for any shooting situation.