Springfield Armory 1873 Trapdoor Rifle 31" Barrel

The Springfield Model 1873 "Trapdoor" was the first standard-issue breech-loading rifle adopted by the U.S. Army. While the official factory blueprint for the standard full-length Infantry Rifle specified a 32.6-inch barrel (often listed in generic descriptions as roughly 32 to 33 inches), it is incredibly common for historical listings, auctions, and modern owners to measure or refer to this configuration as a 31-inch or 32-inch barrel class model.