.450/400 Nitro Express

Not to be confused with .450 Nitro Express or .500/450 Nitro Express.

The .450/400 Nitro Express is a Nitro Express rifle cartridge that is produced in three case lengths: 23⁄8-inches, 3 inches and 31⁄4-inches,^[2] and is intended for use in single shot and double rifles. The 3-inch and 31⁄4-inch versions are considered classic Nitro Express cartridges.

.450/400 Nitro Express (31⁄4-inch)
.450/400 31⁄4 inch Nitro Express in a line up.
Type	Rifle
Place of origin	United Kingdom
Production history
Designer	Kynoch, Jeffery, and others
Designed	1899
Manufacturer	Various
Produced	1899–present
Specifications
Parent case	.450/400 Black Powder Express
Case type	Rimmed, bottleneck
Bullet diameter	.405 in (10.3 mm)
Neck diameter	.432 in (11.0 mm)
Shoulder diameter	.502 in (12.8 mm)
Base diameter	.544 in (13.8 mm)
Rim diameter	.614 in (15.6 mm)
Rim thickness	.042 in (1.1 mm)
Case length	3.25 in (83 mm)
Overall length	3.85 in (98 mm)
Primer type	Kynoch #40
Ballistic performance
Bullet mass/type Velocity Energy 400 gr (26 g) 2,150 ft/s (660 m/s) 4,110 ft⋅lbf (5,570 J)
Test barrel length: 26 inches Source(s): Kynoch[1] & Barnes[2]

Development

Both the .450/400 23⁄8-inch NE and .450/400 31⁄4-inch NE were created by loading the .450/400 Black Powder Express cartridges of both case lengths with smokeless cordite.

.450/400 23⁄8-inch Nitro Express

The .450/400 23⁄8 inch Nitro Express was loaded with a 400 gr. RN bullet with 42 or 43 grains of cordite, and meant for use in newer rifles chambered for it, 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 31⁄4-inch Nitro Express

The .450/400 31⁄4-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,^[2] 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.

Additionally, the caliber had to be standardised, slight variations existed in both the rifles and the low-pressure black powder cartridges produced by different manufacturers, the bullet diameter is nominally given as .405 inches, bore as large as .411 existed, not a significant problem in black-powder rifles. In Nitro Express loadings, an undersized bullet in an oversized bore may experience accuracy issues while an oversized bullet fired in an undersized bore may cause a catastrophic failure in the firearm.^[2]

The .450/400 31⁄4-inch Nitro Express fires a 400 gr. jacketed bullet ahead of a charge of 56 - 60 gr. of cordite at a velocity of 2,150 ft/s (660 m/s). This cartridge is considered unsafe to use for older rifles chambered for the black powder version of this cartridge due to higher pressures generated by this loading. .450/400 31⁄4-inch Nitro Express rifles are heavier and were considered as the minimum cartridge necessary when hunting dangerous game.

Use

The .450/400 NE in both the 3-inch and 31⁄4-inch versions were extremely popular in Africa and India, prior to the introduction of the .375 Holland & Holland they were considered the best all-round African hunting caliber. Both cartridges were extremely popular in India with Maharajas and British sportsmen for hunting tiger.^[3]

In his African Rifles and Cartridges, John "Pondoro" Taylor stated the 3-inch and 31⁄4-inch .450/400 NE were adequate for all African game in almost all conditions when used by an experienced hunter.^[4]

See also

• Nitro Express
• List of rifle cartridges
• 10 mm caliber other cartridges of similar caliber size.