<p> This study examines whether 500 solid copper bullets fired from a 9mm firearm would have a significant effect on the individual rifling characteristics of the barrels of a Glock Model 17, a Beretta Model M9, and a Taurus Model PT 92 AF. Five silicone casts of each barrel bore were prepared over the course of this study. The casts were used to compare and evaluate the wear on the rifling of each barrel and note any changes that may have occurred during the progression of the study. The bullets were purchased as reloading components and were tested for hardness in addition to Energy Dispersive Spectroscopy (EDS) analysis. The bullets used for examination were collected at the start, throughout the experiment, and after the firearm had been cleaned following the 500 firings. The bullets, as well as barrel casts, were analyzed using a Leica FS C comparison microscope. Results from the analysis indicate the bullets do not obturate and they do not engage with the grooves of each barrel. Analysis of land impressions show striations that deteriorate or disappear completely; while others appear over the course of firing the 500 copper bullets. Regarding the influence of the bullet wear on the individual rifling characteristics, the striations of each firearm barrel were permanently changed to the point where bullet identification no longer was possible.</p><p>