Study results broadly confirm the findings of previous studies in finding that although there were some alight differences in the class and individual characteristics observed over time, these changes were not significant, and it was possible to conclusively match the last fired cartridge case to the first for all five pistols. The most obvious slight difference in class characteristics was found in the extractor mark length for the Canik 55, Yavuz 16, and the Sahin 08 self-loading pistols, as well as in the extractor mark width for the Sahin 08. For the Sahin 08, the most significant change in the extractor mark measurement occurred on the first 10 fired cartridge cases, creating the largest standard deviation for this class characteristic for all 5 pistols. There were some slight changes in individual gun characteristics identified between the first and last cartridge case fired in each pistol; however, these were not significant and did not influence the ability of the firearms examiner to match the samples. The class and individual characteristics were identified for each pistol, and the first fired cartridge case was compared with the subsequent consecutive 250th fired case for each pistol. 10 tables, 5 figures, and 13 references