Compositional analysis of the gunpowder additives nitroglycerin, diphenylamine, and ethyl centralite provides information that can associate residue samples with unfired gunpowder. The researchers evaluated the composition of seven reloading smokeless gunpowders, both in bulk and as single particles, by ultrasonic solvent extraction/capillary electrophoresis. Handgun-fired residues obtained from three common weapon calibers loaded with the known reloading powders were compared with the unfired powders. In general, the composition of the residues was similar to that found in the unfired powders. For double-base powders, comparing the ratio of the propellant (P) to the total amount of stabilizer (S) for both residue and gunpowder samples proved to be a useful measurement for identification. This P/S ratio showed that the additives in the residues did not greatly change relative to the unfired powder, providing a useful indicator to aid in forensic powder and residue evaluation. 3 tables, 6 figures, and 11 references