Volume 43, Issue 3 (May 1998)
Antimony Enrichment on the Bullets' Surfaces and the Possibility of Finding It in Gunshot Residue (GSR) of the Ammunition Having Antimony-Free Primers
Projectiles of twenty brands of ammunition were examined by scanning electron microscopy/energy dispersive X-ray spectroscopy (SEM/EDX). In all of them antimony enrichment was found on the surface (about 10 µm depth or less) of the lead alloy as compared to the bulk. In some of the bullets the enrichment was high—as much as tens of times the bulk concentration. Concentration depth profiles in several of the projectiles were also studied by Auger electron spectroscopy (AES), and much higher concentrations of antimony on the surface than in the bulk were observed even where this effect could hardly be detected by SEM/EDX. Shooting tests were carried out using ammunition having antimony-free primers and in which the highest content of antimony on the surface of projectiles was observed. A very small percentage of gunshot residue particles containing antimony was found in these tests.