The .45-70, also known as the .45-70 Government, .45-70 Springfield, and .45-21⁄10" Sharps, is a .45 caliber rifle cartridge originally holding 70 grains of black powder that was developed at the U.S. Army's Springfield Armory for use in the Springfield Model 1873. It was a replacement for the stop-gap .50-70 Government cartridge, which had been adopted in 1866, one year after the end of the American Civil War, and is known by collectors as the "Trapdoor Springfield".
From left, .30-06, .45-70, and .50-90 Sharps
Cartridge profile and headstamp
Magnum Research BFR in .45/70 Govt
The Springfield Model 1873 was the first standard-issue breech-loading rifle adopted by the United States Army. The rifle, in both full-length and carbine versions, was widely used in subsequent battles against Native Americans.
Springfield model 1873
Model 1873 Springfield Rifle
Reenactment firing a Springfield Model 1873 breech-loading rifle at Fort Mackinac in 2008
Geronimo (right) holding a Springfield Model 1873 alongside his fellow Apache warriors in 1886