This is a nice condition and well-marked example of the US Model 1855 Socket Bayonet; the standard socket bayonet used on all .58 caliber US rifle muskets from the Model 1855 through the Model 1870 .50-70 Allin Conversion Rifles. The Model 1855 bayonet was the most used bayonet of the American Civil War era, with well over one million produced by the National armories and a variety of contractors during the mid-1800s. The Model 1855 introduced a new shape to the shoulders for the bayonet blade, which took on a smoothly tapered shape with this pattern, eliminating the sharp shoulders that had been typical from the pre-1816 pattern US bayonets through the Model 1835 socket bayonet. This new blade shape would remain in use with the Model 1873 bayonet for the Model 1873 and all subsequent “Trapdoor” rifles that accepted a socket bayonet.

This particular US Model 1855 .58 socket bayonet is in about VERY GOOD condition. It retains some of its original arsenal bright polish but has aged and dulled and now shows evenly distributed patches of oxidized age discoloration. The metal of the bayonet is mostly smooth but does show some scattered areas of minor surface roughness on the blade, with a pinkie nail sized patch of oxidized roughness being the most noticeable patch, near the base of the fuller. The socket shows some more moderately freckled oxidized discoloration and minor surface roughness. Some of this might be removable with a careful, light cleaning. The bayonet is full-length and retains its original locking ring and tension screw, which function exactly as they should. The face of the blade is clearly and deeply stamped with the letters US, over a smaller letter S. The meaning of the smaller S is generally considered to indicate the bayonet was manufactured at the US Armory at Springfield, MA. However, it is not clear if that is what it represents. The blade also shows a punch dot above the “US”, which is typically a hardness test mark. The upper rear of the socket is also marked with a small capital letter A, the mark of Springfield Armory sub-inspector Orville Wood Ainsworth. 

Ainsworth is most famous for inspecting the first thirteen months of Colt Model 1873 Single Action Army revolver production, including the desirable “Custer Range” revolvers. Ainsworth had a 43-year long tenure at Springfield, working as a sub-inspector from 1831 through 1874, making him one of the longest employed workers for the Arsenal. During the Civil War Ainsworth spent time at Colt inspecting Model 1860 Army revolvers from September 1861 through at least the spring or summer of the following year. His marks are found on Colt Model 1860 revolvers ranging from #8487 through #62738. Ainsworth also inspected Colt Model 1861 Navy Revolvers, and Remington New Model Army revolvers. Clearly, between his visits to these various Ordnance Department contractors, he found time to inspect at least some bayonets at Springfield. Although some people feel that the “A” marked bayonets were bayonets inspected by Ainsworth and delivered by Colt with their Model 1861 Special Model Rifle Muskets, I have found no research to indicate that Ainsworth inspected bayonets, or even Model 1861 muskets, during his tenure at Colt. He did, however, inspect US .58 caliber contract rifle muskets produced from the Savage Revolving Firearms Company, as well as from the Providence Tool Company, Parker, Snow & Co., Amoskeag and Remington.

If you have been wanting to add a nice example of a US Model 1855 bayonet to your collection, with the desirable Ainsworth inspection mark, this would be a good one. This bayonet would also be a nice addition to the display of a US Model 1861/63/64 pattern .58 rifle musket with a similarly lightly mottled bright appearance.