Antique US Model 1855 Socket Bayonet measuring 21″ overall with a 18″ blade. US stamped on the ricasso area of the blade. Shows a a gray/silver age patina with scattered pitting. These bayonets fit the Model 1855 and M1861-62-63 Muskets. This also fits the pre-Model 1873 Springfield Trapdoor Bayonets. These were not blued, they were finished bright and had a larger socket, inside diameter of.