The .42 caliber Berdan cartridge was part of the weapon system designed by Hiram Berdan, an American gun maker who the Russians had gone to in order to improve their infantry weapons.  Physically the cartridge appears as did many rounds of the day.  A lubricated paper wrapped .42 caliber bullet in a brass case that used a primer rather than a percussion cap to ignite the gun powder within it.

At the time of its introduction the Berdan rifle cartridge was one of the more powerful cartridges in military service.  The bullet weighed about 386 grains and was made of 99% lead and 1% antimony.  The powder charge varied by cartridge: 77 grains for the rifle cartridge and 69.5 grains for the carbine cartridge.  Cartridge types can be determined by their color. 

The cartridge was used in a variety of weapons during its years of service.  All of the .42 caliber Berdan rifles (Infantry, Dragoon, and Cossack) used it, and when the Gorlov gatling gun was introduced in Russia, it too was cambered in .42 caliber.  The discovery of smokeless powder in the late 19th century would mean an end to the .42 caliber cartridge, as arms manufacturers began to shift towards smaller calibers with increased range.   In Russia the 7.62x54R cartridge and the Mosin-Nagant rifle system would move in to replace the .42 caliber Berdan cartridge.