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Unleaded hunting: Are copper bullets and lead-based bullets equally effective for killing big game?

  • Sigbjørn StokkeEmail author
  • Jon M. Arnemo
  • Scott Brainerd
Lead Use in Hunting


Semi-jacketed lead-cored or copper-based homogenous rifle bullets are commonly used for hunting big game. Ever since their introduction in the 1990’s, copper-based bullets have not been widely accepted by hunters due to limited supply, higher expense, and the perception that they exhibit inferior killing efficiency and correspondingly higher wounding rates. Here, we present data showing that animal flight distances for roe deer, red deer, brown bear, and moose dispatched with lead- or copper-based hunting bullets did not significantly differ from an animal welfare standardized animal flight distance based on body mass. Lead-cored bullets typical fragment on impact, whereas copper-based bullets retain more mass and expand more than their leaden counterparts. Our data demonstrate that the relative killing efficiency of lead and copper bullets is similar in terms of animal flight distance after fatal shots. Hunters that traditionally use lead bullets should consider switching to copper bullets to enhance human and environmental health.


Animal flight distance Animal welfare Hunting bullet expansion Killing efficiency Lead and copper ammunition Wound ballistics 



This study was carried out in collaboration with the Swedish Association for Hunting and Wildlife Management and the Finnish Wildlife Agency and partly funded by Norwegian Environment Agency. We thank L. Botten, who carried out the laboratory work on retrieved bullets, and Arne Söderberg for his inestimable work to gather and systematize the brown bear data. We are grateful to A/S Norske Shell who enabled our sampling of culling data from their effort to remove roe- and red deer from their plant site at Nyhamna, Norway. And finally, we thank thousands of anonymous hunters in Norway, Sweden, and Finland, who submitted bullets and provided data on hunting practices.

Supplementary material

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Supplementary material 1 (PDF 18 kb)


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Copyright information

© Royal Swedish Academy of Sciences 2019

Authors and Affiliations

  1. 1.Norwegian Institute for Nature ResearchTrondheimNorway
  2. 2.Inland Norway University of Applied SciencesKoppangNorway
  3. 3.Division of Wildlife ConservationAlaska Department of Fish and GameFairbanksUSA

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