Metallic Ammunition of the United States Civil War: Characterization of the Case, Primer and Gunpowder by Scanning Electron Microscopy/Energy Dispersive X-Ray Spectroscopy

This study presents a Scanning Electron Microscopy and Energy-Dispersive X-ray Spectroscopy (SEM/EDS) characterization of three American Civil War era ammunition: the .56-52 Spencer, .56-56 Spencer, and .50 US carbine centerfire. Analysis revealed the Spencer rimfire cases consist of pure copper, likely to prevent the embrittlement caused by mercury fulminate in the primer, whereas the latter .50 US carbine centrefire case utilizes a brass alloy. The propellant was confirmed to be traditional black powder. Notably, traces of silicon and aluminum detected within the primer and propellant residues were thoroughly investigated. The lack of systematic glass markers suggests these elements originated from impurities or degraded organic binders, rather than intentionally added glass frictionators. Ultimately, this research addresses a gap in the literature regarding the material composition and degradation of mid-19th-century ammunition.