U.S. Springfield Model 1866 2nd Allin Conversion Trapdoor Rifle .50-70 (64864)

NSN. Manufactured post-Civil War by Springfield Armory using converted surplus muskets, chambered in .50-70 Government,40" round rifled barrel. The bore is bright and shiny with strong, well-defined rifling noted throughout. The metal has aged to a smooth grey patina, while the breech block retains the majority of its original black finish, providing nice contrast. Factory markings remain sharp and clearly legible. The stock shows expected handling impressions with a visible cartouche on the left side. The Model 1866 represents the improved “Second Allin Conversion,” refining the earlier trapdoor system and marking an important step in the U.S. military’s transition to metallic cartridge firearms. The action is mechanically sound and functions correctly.