This is a VERY FINE condition example of the US Model 1855 Mainspring Vise. The vise was adopted with the US Model 1855 rifle and rifle musket, and remained in use through the Models 1861, 1861 Special Model, 1863 and 1864 rifle muskets of the Civil War era, as well as with the Allin conversions, early .50-70 Trapdoor alterations and early purpose-made .50-70 Trapdoors. The vise even remained in service through the first issuances of the Model 1873 Trapdoor rifle. The tool was finally made obsolete by the adoption of the Model 1879 combination tool for the use with the Trapdoor series of long arms.
The vise has slightly offset jaws and a large thumbscrew, which allow a mainspring to be compressed for removal or insertion in a rifle, musket, or carbine lock. The tool retains about 85%+ of its original arsenal blued finish. The metal does show some scattered surface oxidation and some flecks of discoloration and freckles of minor oxidation on the surface. It is crisply and deeply marked with an upside-down U S on the upper lug that the compression screw passes through. Most US military gun tools from the mid-19th century that are “US” marked, are considered to be the products of the Harpers Ferry Arsenal. However, that is not a provable assertion, to my knowledge.
The tool is fully functional and operates smoothly and correctly in every way. This would be a nice addition to a display of Civil War era gun tools, or as a functional tool for use when working on your Civil War era rifles and muskets.
Please note that the images are much larger than the actual tool is! This allows you to see condition and details easily.