title: Performance of lead-free versus lead-based hunting ammunition in ballistic soap.
abstract: BACKGROUND
  Lead-free hunting bullets are an alternative to lead-containing bullets which cause health risks for humans and endangered scavenging raptors through lead ingestion. However, doubts concerning the effectiveness of lead-free hunting bullets hinder the wide-spread acceptance in the hunting and wildlife management community.
  
  
  METHODS
  We performed terminal ballistic experiments under standardized conditions with ballistic soap as surrogate for game animal tissue to characterize dimensionally stable, partially fragmenting, and deforming lead-free bullets and one commonly used lead-containing bullet. The permanent cavities created in soap blocks are used as a measure for the potential wound damage. The soap blocks were imaged using computed tomography to assess the volume and shape of the cavity and the number of fragments. Shots were performed at different impact speeds, covering a realistic shooting range. Using 3D image segmentation, cavity volume, metal fragment count, deflection angle, and depth of maximum damage were determined. Shots were repeated to investigate the reproducibility of ballistic soap experiments.
  
  
  RESULTS
  All bullets showed an increasing cavity volume with increasing deposited energy. The dimensionally stable and fragmenting lead-free bullets achieved a constant conversion ratio while the deforming copper and lead-containing bullets showed a ratio, which increases linearly with the total deposited energy. The lead-containing bullet created hundreds of fragments and significantly more fragments than the lead-free bullets. The deflection angle was significantly higher for the dimensionally stable bullet due to its tumbling behavior and was similarly low for the other bullets. The deforming bullets achieved higher reproducibility than the fragmenting and dimensionally stable bullets.
  
  
  CONCLUSIONS
  The deforming lead-free bullet closely resembled the deforming lead-containing bullet in terms of energy conversion, deflection angle, cavity shape, and reproducibility, showing that similar terminal ballistic behavior can be achieved. Furthermore, the volumetric image processing allowed superior analysis compared to methods that involve cutting of the soap blocks.
authors.affiliation: Experimental Molecular Imaging, University Hospital, RWTH Aachen University, Aachen, Germany.
authors.forename: Felix
authors.initials: F
authors.lastname: Gremse
authors.affiliation: Leibniz Institute for Zoo and Wildlife Research, Berlin, Germany.
authors.forename: Oliver
authors.initials: O
authors.lastname: Krone
authors.affiliation: Experimental Molecular Imaging, University Hospital, RWTH Aachen University, Aachen, Germany.
authors.forename: Mirko
authors.initials: M
authors.lastname: Thamm
authors.affiliation: Experimental Molecular Imaging, University Hospital, RWTH Aachen University, Aachen, Germany.
authors.forename: Fabian
authors.initials: F
authors.lastname: Kiessling
authors.affiliation: Laboratory Animal Science, University Hospital, RWTH Aachen University, Aachen, Germany.
authors.forename: René Hany
authors.initials: RH
authors.lastname: Tolba
authors.affiliation: Wildlife Biology, Management and Hunting Practice, HNE Eberswalde, Eberswalde, Germany.
authors.forename: Siegfried
authors.initials: S
authors.lastname: Rieger
authors.affiliation: Wildlife Biology, Management and Hunting Practice, HNE Eberswalde, Eberswalde, Germany.
authors.forename: Carl
authors.initials: C
authors.lastname: Gremse
mesh_terms: D005389:Firearms; D005780:Gelatin; D021621:Imaging, Three-Dimensional; D007854:Lead; D014057:Tomography, X-Ray Computed
chemical_list: D007854:Lead; D005780:Gelatin