Date of Award
Spring 5-2025
Document Type
Thesis
Degree Name
Master of Science (MS)
Department/Program
Forensic Science
Language
English
First Advisor or Mentor
Peter Diaczuk
Second Reader
Jack Hietpas
Third Advisor
Andrew Winter
Abstract
The goal of this study was to determine alternative ways to connect a polymer-coated bullet to the handgun from which it was fired. Polymer-coated bullets are lead projectiles encased in a synthetic coating, which may vary between brands and/or models, to reduce barrel friction and heavy metal exposure. Federal Syntech® Total Synthetic Jacket (TSJ) ammunition presents unique challenges to firearms examiners as its synthetic coating may not retain the individualizing striations found in traditional unjacketed or metal-jacketed bullets.
In this study, 9mm TSJ ammunition was fired through multiple traditionally rifled aftermarket Glock barrels. Cloth targets were set up at varying distances to determine at what distances the residue could be recovered. The feed ramp of each barrel was examined after discharge and bore brushes were used to remove residue from the bore for inspection.
The ejection distance of polymer fragments was found to have significant variation, with the barrel seemingly playing a large factor. Recovered fragments were found to sometimes contain pitting, a characteristic documented in other studies utilizing this ammunition. Red residue consistent with TSJ bullet shavings was found on the feed ramp in over 75% of trials and on within the barrel bore residue in 30% of trials. The results show that recovery of this residue on the feed ramp seems to be influenced by bullet weight and barrel used. This study suggests that, in addition to the findings of ejected synthetic residue on cloth targets, the interior of the firearm may also contain jacketing residue.
Recommended Citation
Frazer, Ethan A., "Transfer of Material Derived from Polymer-Jacketed Bullets During Cycling and Discharge" (2025). CUNY Academic Works.
https://academicworks.cuny.edu/jj_etds/351
