This article deals with the study of an assemblage of scrap bronze guns recovered from the Delta III site, identified as a Dutch merchant ship lost in the port of Cadiz, Spain, about the third quarter of the seventeenth century. This kind of remains is seldom preserved and therefore stands as a unique source for addressing modern bronze gunfounding. Its main characteristics and drawbacks were outlined and discussed on historical and archaeological grounds. The gun remains and casting by-products were recorded, and pieces were identified through their design, decoration, and marks. A metallurgical study of selected samples was carried out by visual inspection and microstructural and chemical analyses by light microscopy and scanning electron microscopy coupled with energy-dispersive X-ray spectroscopy. A better understanding of the quality and manufacturing process of the pieces and the conditioning factors of the failed casting was achieved by this approach. Results provided new insights into the gunfounding process, with emphasis on a renowned atelier of German bell and cannon founders, along with the associated international markets and recycling practices. ; This research was developed with the support of the Society for Archaeological Sciences, through the SAS ECR Research Support Award (2021), granted to Nicolás C. Ciarlo. His studies at the University of Cadiz were also supported by the National Scientifc and Technical Research Council (CONICET), through the Support Program for International Research Stays. The equipment and funding to conduct the characterisation of samples were provided by Manuel Bethencourt, chair of the Laboratory of Studies and Conservation of Culture Heritage (LEC-PH) at the University of Cadiz, through a grant from the Spanish State Research Agency, Ministry of Science, Innovation and Universities (State Plan I+D+i 2017–2020, EQC2018-004947-P).