.500 Nitro Express
The .500 Nitro Express is a .510 caliber (12.7 mm) big bore hunting cartridge. It was designed for use in single shot and double rifles. The cartridge is available in two lengths: a 3 inch and a 3.25 inch version. The cartridge was designed for use against large dangerous game species in Africa and India.

History and Origins

The nomenclature .500 Nitro Express refers to a one of three specific loading of the .500 Express case. The other loadings are now called (for the sake of clarity) the .500 Black Powder Express
.500 Black Powder Express
The .500 BPE or Black Powder Express was first used in a Purdey Double Express rifle in the 1860s. It is very similar to the .50-140 Sharps cartridge....

 (BPE) and .500 Nitro for Black Powder (Nitro for BPE). The names given to these loadings are of more modern origin to help one differentiate between the them. The original cartridge was simply known as the .500 Express. The cartridge is one of the original Express cartridges which originated in the black powder era and made the transition into the smokeless powder era.

The .500 Black Powder Express, as the name indicates was designed for use with black powder. It is unknown as to who or which company originally designed the cartridge except that it was designed sometime in the 1860s in the United Kingdom
United Kingdom
The United Kingdom of Great Britain and Northern IrelandIn the United Kingdom and Dependencies, other languages have been officially recognised as legitimate autochthonous languages under the European Charter for Regional or Minority Languages...

. Several manufacturers of firearms produced rifles and loaded ammunition for the cartridge type, however significant differences and veriations existed between manufacturers. For the most part, due to the relatively low working pressures of these rifles and ammunition there was little to no danger associated with the use of these cartridges in a particular rifle.

The .500 Nitro for Black Powder cartridge used the same general case type as the .500 Black Powder Express but was loaded with cordite
Cordite is a family of smokeless propellants developed and produced in the United Kingdom from 1889 to replace gunpowder as a military propellant. Like gunpowder, cordite is classified as a low explosive because of its slow burning rates and consequently low brisance...

 instead of black powder and appeared on the scene sometime in the 1890s. The cartridge was intended for firearms designed to fire the .500 Black Powder Express and pressures were kept low enough so as to operate safely in these older black powder firearms yet provided a substantial increase in performance over the black powder loaded cartridge.

Cordite which was invented in 1889 gave cartridges a greater performance envelope than black powder at the expense of pressure. Rifle that were designed for use with cordite cartridges required stronger actions which were able to withstand the significantly higher pressures to take advantage of the increase in performance offered by cordite. As the working pressure of the .500 Nitro Express cartridge was significantly higher than the black powder cartridge, variations between manufacturers of the same ammunition would result in damage to the firearms and injury to the shooter. For this reason there is an acknowledged standard between manufacturers for the .500 Nitro Express cartridge but not for the earlier black powder cartridge.

Since cordite contained guncotton (nitrocellulose) and nitroglycerine, cartridges this formulation were often prefixed by “nitro” as a means of differentiation. The suffix “Express” denotes the comparatively higher velocity of the cartridge drawing from the analogy of the express trains from that period of time.

After World War II and as many of colonies of the United Kingdom gained independence the popularity of the Nitro Express cartridges began to waned. Mismanagement of renewable resources, poor wildlife management, misguided government policies and poaching in the newly independent states were factors which prevented big game hunting in these states. A recognition by many of these states that proper wildlife management and policies could attract much needed foreign currency has been an incentive in creating a more attractive environment which accommodates trophy and dangerous game hunting in Africa. This renewed interest in dangerous game hunting in Africa has in turn renewed the interest in the Nitro Express cartridges including the .500 Nitro Express.

Both the 3 inch version and the 3.25 inch version of the cartridge are loaded to the same performance level .

Design and Specifications

The large capacity of the .500 Express case is due to the cartridge originally being designed to use black powder as a propellant. The 3 inch case has a case capacity of 138 grains of H2O (8.96 cm3) while the 3.25 inch case has a capacity of 158 grains of H2O (10.30 cm3).

Commission Internationale Permanente pour l'Epreuve des Armes à Feu Portatives
The Commission Internationale Permanente pour l'Epreuve des Armes à Feu Portatives is an international organisation whose members are 14 states, mainly European....

 regulates the 3 inch version of the cartridge but not the 3.25 inch version.

The CIP recommends 7 groove barrel with a twist rate of 1:15. The barrel is to have a groove Ø of 13 mm (0.511811023622047 in) and a bore Ø of 12.7 mm (0.5 in) with a grove width of 3.61 mm (0.142125984251969 in). Maximum average peak pressure for the cartridge is 2800 bar (40,610.6 psi) for the 3 in (76.2 mm) version of the cartridge. While the CIP does not regulate the 3.25 in (82.6 mm) version of this cartridge this cartridge is loaded to a lower pressure of 2700 bar (39,160.2 psi). Except for length and overall length, the 3.25 in (82.6 mm) version of the has the similar dimensions as the 3 in (76.2 mm) case.


The .500 Nitro Express provided a leap in stopping power and performance over its black powder rivals. The .500 Nitro Express was loaded with jacketed bullets giving it far better results against dangerous game than the .500 BPE or Nitro BPE. Furthermore the bullets had better sectional density which taken together with the fact that the bullet was jacketed, provided far greater penetration on dangerous game such as Cape buffalo and African elephant.
A Comparison of .500 Express Cartridge Loadings
Cartridge Bullet Muzzle Velocity Muzzle Energy Comments
.500 Black Powder Express 440 gr 1500 ft/s (457.2 m/s) 2198 ft·lbf (2,980.1 J) Original black powder load. Similar to the .50-140 Sharps/Winchester
.50-140 Sharps
The .50-140 Sharps rifle cartridge is a black powder cartridge that was introduced in 1884 as a big game hunting round. It is believed to have been introduced for the Sharps-Borchardt Model 1878 rifle. The cartridge is very similar to the .500 Nitro Express....

.500 Nitro for Black Powder 440 gr 1900 ft/s (579.1 m/s) 3528 ft·lbf (4,783.3 J) Kynoch nitro load for BP rifles.
.500 Nitro Express 570 gr FMJ/SP 2150 ft/s (655.3 m/s) 5850 ft·lbf (7,931.5 J) Kynoch NE load
Values from various sources reflecting factory loading for each cartridge type.

When compared to the then more popular .450 Nitro Express, the .500 Nitro Express fires a heavier bullet with about a 25% greater cross-sectional area and similar sectional density at an equal velocity. The typical .500 Nitro Express generates about 20% more energy than the .450 Nitro Express cartridge. The .500 Nitro Express is considered to be superior to the smaller caliber Nitro Express cartridges in killing power.

The .500 Nitro Express cartridge produces substantial recoil. Factory ammunition typically produce 85 ft·lbf (115.2 J) of recoil energy at a recoil velocity of 23.5 ft/s (7.2 m/s) using a 10 lb (4.5 kg) rifle which is similar to the recoil of the .458 Lott fired in an 8 lb (3.6 kg) rifle.
Performance Characteristic .500 Nitro Express Ammunition
Cartridge Criteria Muzzle 25 yards (22.9 m) 50 yards (45.7 m) 75 yards (68.6 m) 100 yards (91.4 m) 125 yards (114.3 m) 150 yards (137.2 m) 175 yards (160 m) 200 yards (182.9 m)
Hornady 570 gr DGS/DGX Velocity 2100 ft/s (640.1 m/s) 2033 ft/s (619.7 m/s) 1967 ft/s (599.5 m/s) 1902 ft/s (579.7 m/s) 1839 ft/s (560.5 m/s) 1777 ft/s (541.6 m/s) 1717 ft/s (523.3 m/s) 1658 ft/s (505.4 m/s) 1601 ft/s (488 m/s)
Energy 5581 ft·lbf (7,566.8 J) 5229 ft·lbf (7,089.6 J) 4895 ft·lbf (6,636.7 J) 4578 ft·lbf (6,206.9 J) 4279 ft·lbf (5,801.5 J) 3996 ft·lbf (5,417.8 J) 3730 ft·lbf (5,057.2 J) 3479 ft·lbf (4,716.9 J) 3244 ft·lbf (4,398.3 J)
Bullet Drop -1 in 0.1 in (0.254 cm) 0.6 in (1.5 cm) 0.6 in (1.5 cm) 0 in (0 cm) -1.3 in (-3.3 cm) -3.2 in -5.9 in -9.4 in
Rifle sighted in 1 inch (2.5 cm) above bore axis

The trajectory of the .500 Nitro Express is similar to that of the .30-30 Winchester cartridge with a 170 gr Flat Nose bullet. The Hornady DGX and DGS ammunition which has the performance characteristics of typical .500 NE ammunition has an MPBR (maximum point blank range) of 197 yd (180.1 m). For these reasons the .500 Nitro Express should be considered a short range cartridge.

Sporting Usage

The .500 Nitro Express was designed as a hunting cartridge for use against large and heavy dangerous game such as Cape buffalo, rhinoceros and African elephant. The 570 gr bullet has excellent sectional density which is required for work against dangerous game out to 110 yd (100.6 m) and provides adequate penetration for the hunting of thick skinned dangerous game. It should be noted that some preofessional African hunters have complained that the taper of the 570 grain bullet, toward the nose, increases the incidents of bullet "fish tailing" during penetration causing the bullet to not maintain a straight course. The 570 grsolid bullet is used mainly elephant but was also used in some situations for Cape buffalo and rhinoceros when the extra penetration provided by these non-expanding bullets was necessary. Mated with the 570 gr solid bullet, the .500 Nitro Express would become the quintessential elephant cartridge on the African savanna. The round nose soft point 570 gr bullet was used on most other game species.

Unlike some of the more modern cartridges such as the .460 Weatherby
.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...

, the .500 Nitro Express it is not considered too over powered for use against the big cats. The big cats do not require the more stoutly constructed bullet as they neither heavy bodied nor do they have thick skin and are best served with a more lightly constructed bullet that is capable of expanding quickly such as the 570 gr A-Square Lion Load or the Woodleigh 450 gr Soft Nose.

In North America cartridges such as the .500 Nitro Express see little use as no North American game species requires the cartridges in the same class as the .500 Nitro Express. Nevertheless, there can be no doubt that the cartridge would be a very effective stopper against a charge by one of the large bears or bison should it be carried in the field.


During the heyday of hunting every major manufacturer of British dangerous game rifles produced ammunition for the .500 Nitro Express rifles. However, by the 1960s only Kynoch was left producing ammunition. Due to the lack of interest Kynoch ended production of the Nitro Express cartridges in 1970.

As African hunting safaris became more popular from the 1990s onward there has been a renewed interest in the cartridge. Whereas before mainstream American ammunition manufacturers hardly ever showed an interest in the British big bore ammunition, demand created by American hunters spurred on companies such as A-Square, Federal and Hornady to offer Ammunition for these cartridge types. Ely which had purchased Kynoch, licensed the brand name to Kynamco of the United States. Kynamco now offers British sporting cartridges including the nitro express cartridge for sale using the Kynoch brand name. Norma of Sweden has also begun to offer this cartridge for sale.

See also

  • Nitro Express
    Nitro Express
    The Nitro Express series of cartridges are used in large-bore hunting rifles, also known as elephant guns or express rifles. They are named after the propellant they use, cordite, which is composed of nitrocellulose and nitroglycerine...

  • .577 Nitro Express
    .577 Nitro Express
    The .577 Nitro Express is a rimmed cartridge in the Nitro Express series of big-game hunting ammunition. It is also known as the .577 Nitro Express 3" and there is a variant called the .577 Nitro Express 2.75"...

  • .600 Nitro Express
    .600 Nitro Express
    The .600 Nitro Express is a round in the Nitro Express series which was introduced in 1903. It is the second largest calibre in the Nitro Express line, exceeded only by Holland & Holland's .700 Nitro Express round.-Overview:...

  • List of cartridges by caliber
  • List of rifle cartridges
  • 12 mm caliber
    12 mm caliber
    This article lists firearm cartridges which have a bullet in the to caliber range.*Length refers to the cartridge case length.*OAL refers to the overall length of the cartridge.*Bullet refers to the diameter of the bullet....

  • 13 mm caliber
    13 mm caliber
    This article lists firearm cartridges which have a bullet in the caliber range and greater.*Length refers to the cartridge case length.*OAL refers to the overall length of the cartridge.*Bullet refers to the diameter of the bullet....


  • Barnes, Frank C., ed. by John T. Amber. ".500 Nitro Express (3")", in Cartridges of the World, pp.231 & 236. Northfield, IL: DBI Books, 1972. ISBN 0-695-80326-3.
  • ______ and _____. ",458 Winchester", in Cartridges of the World, p. 64. Northfield, IL: DBI Books, 1972. ISBN 0-695-80326-3.
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