.577 Nitro Express

.577 Nitro Express 3-inch
The .577 Nitro Express is a large small-arms cartridge. In this picture, it is compared to one of the smallest cartridges, a .22 CB.
Type	Rifle
Place of origin	United Kingdom
Production history
Designed	1890s
Variants	.577 Nitro Express 2¾-inch & .577 Nitro Express 3¼-inch
Specifications
Parent case	.577 Black Powder Express
Bullet diameter	.584 in (14.8 mm)
Neck diameter	.608 in (15.4 mm)
Base diameter	.660 in (16.8 mm)
Rim diameter	.748 in (19.0 mm)
Rim thickness	.052 in (1.3 mm)
Case length	3 in (76 mm)
Overall length	3.70 in (94 mm)
Primer type	.254
Ballistic performance
Bullet mass/type Velocity Energy 750 gr (49 g) 2,050 ft/s (620 m/s) 7,010 ft·lbf (9,500 J)
Test barrel length: 28 Source(s): Barnes and Kynoch.

The .577 Nitro Express is a large bore centerfire rifle cartridge 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.

The .577 Nitro Express is a straight rimmed .584-inch (14.8 mm) calibre cartridge designed for use in single-shot and double rifles. It has been made in three case lengths based on their respective black-powder .577 Black Powder Express cartidges.

The .577 Nitro Express 2¾-inch is a conversion of the .577 Black Powder Express 2¾-inch, it fires a 750-grain (49 g) projectile at over 1,800 feet per second (550 m/s). Never as popular as the 3-inch version, today it is only available by special order.

The .577 Nitro Express 3-inch is a conversion of the .577 Black Powder Express 3-inch, it fires a 750-grain (49 g) projectile at over 2,050 feet per second (620 m/s). This cartridge was to become the most popular of the three and a standard round for African elephant hunters in the early 20th century.

The .577 Nitro Express 3¼-inch is a conversion of the .577 Black Powder Express 3¼-inch, again it was never as popular as the 3-inch version.

Following the success of the development in 1898 of the revolutionary .450 Nitro Express by John Rigby & Company, achieved by loading the old .450 Black Powder Express with cordite, similar conversions were made to other blackpowder Express cartidges, including the .577 Black Powder Express in its various case lengths.