Examination of firearm gunpowders by scanning electron microscopy/energy dispersive X-ray analysis.

The surfaces of thirty-one gunpowders (GPs) from Winchester, Federal, Hercules, DuPont, and Remington were examined by scanning electron microscopy/energy dispersive X-ray spectroscopy. Particles and surface coatings on 22 of the GPs had compositions of sulfur/potassium/barium or sulfur/potassium detected. Primer-like particles composed of lead/antimony/barium were found on surfaces of twelve GPs. Gunpowders from fifteen different lots of Winchester 9 mm Silvertip® hollow point cartridges were found to vary in GP type (flake and flattened ball) and associated inorganic compounds of sulfur/potassium/barium or sulfur/potassium or one with only potassium. No inorganic particles or coatings were detected on two of these Winchester GPs. The elements from the inorganic compounds on GPs likely contribute to gunshot residue generated by the discharge of a firearm.