.450 Nitro Express also known as the .450 3¼-inch Nitro Express was designed for the purpose of hunting large game such as elephant. This cartridge is used almost exclusively in single shot and double express rifles for hunting in the Tropics or hot climates in general and is a cartridge associated with the Golden Age of African safaris and Indian shikars.

Development

The .450 Nitro Express was the first Nitro Express, developed around 1898 by John Rigby. This cartridge was based on the then popular .450 Black Powder Express case with 70 grains (5 g) of Cordite and a 480-grain (31 g) jacketed bullet. Muzzle velocity is listed at 2,150 feet per second (655 m/s) with 4,909 ft·lbf (6,656 J) of muzzle energy. This straight case has a length of 3.25 in (83 mm) with a .670 in (17.0 mm) rim.

Early cartridges used the black powder case that was designed for around 22,000 psi and not the 34,000 psi that the Cordite load generated. Case extraction was difficult, especially in warmer climates such as Africa and India where the cartridge was primarily used. To remedy this problem, a reinforced case was produced and Kynoch made a reduced load to lower the case pressure. Another problem lay in the sensitivity of Cordite, loads developed in the cool British climate performed differently in the tropical heat of Africa and India, resulting in excessive pressures. The manufacturers responded by developing "tropical loads" with reduced propellant.

The .450/400 Nitro Express is a Nitro Express rifle cartridge that produced in two case lengths, 2⅜-inches and 3¼-inches, intended for use in single shot and double rifles, the latter is considered a classic Nitro Express cartridge.

Development

Both the .450/400 2⅜-inch NE and .450/400 3¼-inch NE were created by loading the .450/400 Black Powder Express cartridges of both case lengths with smokeless cordite.

.450/400 2⅜-inch Nitro Express

The .450/400 2⅜ inch Nitro Express was loaded with a 400 gr. RN bullet with 42 or 43 grains of cordite and was meant for use in newer rifles chambered for the .450/400 2⅜ inch case as this loading generates greater pressure than the Black Powder Express versions of the cartridge.

.450/400 3-inch Nitro Express

This cartridge is better known as the .400 Jeffery Nitro Express.

.450/400 3¼-inch Nitro Express

The .450/400 3¼-inch NE conversion was not initially entirely successful, under the increased pressures of the cordite loading the long neck could stick in the chamber causing the rim to pull off at extraction, a problem not encountered under the milder black powder loadings. To counter this, the rim was increased in thickness to .042-inches. W.J. Jeffery & Co further improved the cartridge by reducing the length of the case to 3-inches and moving the neck further forward, creating the .450/400 3-inch NE.

The .476 Nitro Express, also known as the .476 Westley Richards, is a British rifle cartridge introduced by Westley Richards around 1907.

Development

The .476 Nitro Express is one of several rounds (including the .500/465 Nitro Express, .470 Nitro Express, .475 Nitro Express, and .475 No. 2 Nitro Express) developed as a replacement for the .450 Nitro Express following the British Army 1907 ban of .450 caliber ammunition into India and the Sudan, all with comparable performance.

Westley Richards created the .476 Nitro Express by necking down the .500 Nitro Express 3".

Use

Available in single-shot and double rifles, it was less popular than the above mentioned rounds. It is nearly identical in performance to a number of others in the same class.

The .476 is considered adequate for all African and Indian big game, including elephant and rhinoceros. Its ballistics resemble the .458 Winchester Magnum, with a larger diameter bullet; whether this is an advantage remains in dispute.

The .700 Nitro Express (17.8×89mmR) is a big game rifle cartridge made by Holland & Holland, London, England. It was developed in 1988 by Jim Bell and William Feldstein and built by H&H. Feldstein had tried unsuccessfully to get H&H to build a .600 Nitro Express for him, but they had already ceased production. However, when Bell and Feldstein produced the entirely new .700 Nitro Express cartridge, they were able to attract the interest of H&H, which was looking for a new big-bore cartridge. After production began, the backlog of orders was so great that it continued to 2007 and H&H restarted the production of .600 Nitro Express guns.

Specifications

In many respects this cartridge parallels the .600 Nitro Express. It is essentially a scaled-up version of that cartridge, but is somewhat more powerful, and fires a heavier 1000-grain (64.8 g) bullet. The case itself is a completely new case, not simply another case resized. Double rifles are extremely expensive, selling upwards of $260,000 USD in 2015, and have generally been replaced by repeater-rifles using rounds such as the .458 Winchester.