Preliminary Testing Nine test fires were made into individual pieces of the cotton twill test fabric(approximately 12in x 12in) from the three firearms at distances of 6 inches(15 cm), 9 inche(23 cm), and 2 inches(30 cm). A visual examination determined that the patterns produced from the 357 Magnum were excessive for optimal testing and the pat produced from the 380 re of insufficient density for optimal testing conditions. The Ruger P89 chambered in 9mm Luger, produced visual attems at 6 inches(15 cm) and 9 inches(23 cm) that were centrally dense: at 12 inches(30 cm) a greater number visible point reactions were observed. Based on these results the Ruger P98DC with Remington, FMJ, 115 grain ammunition from a distance of 12 inches(30 cm) was chosen for all further test firings. Sodium nitrite solution applied with a cotton swab as a positive control gave a positive Modified t result with the desensitized photographic paper. Griess