1. a single-shot, breechloading .45-caliber rifle used by the U.S. Army from 1867 to 1893.
2. Also called Springfield 1903 . a bolt-operated, magazine-fed, .30-caliber rifle adopted by the U.S. Army in 1903 and used during World War I.
3. a single-shot, muzzleloading rifle of .58-inch caliber, used by the Union Army during the Civil War.
[ after SPRINGFIELD, Mass., site of a federal armory that made the rifles ]