Definitions for ".45-70"
The .45-70 rifle cartridge was developed at the U.S. Army's Springfield Armory for use in the Springfield Model 1873 .45 caliber rifle, known to collectors (but never to the Army) as the "Trapdoor Springfield." The new cartridge was a replacement for the stop-gap .50-70 cartridge which had been adopted in 1866, one year after the end of the American Civil War.