Chapter 7 of the book entitled 'Practical Veterinary Forensics' aims to introduce forensic veterinarians to the scientific concepts underpinning the field of firearms and ballistics. This introduction will enable practitioners to understand wound formation depending on the firearm and ammunition used. \ud \ud Various types of firearms, modern firing mechanisms and ammunition will be explained, together with an introduction to the physical concepts underpinning the four main constituents of the term ballistics; internal, intermediate, external and terminal ballistics. Wound ballistics is a sub-set of terminal ballistics and is specifically discussed to put the physical and chemical scientific concepts into context of forensic veterinary practice. The collection of firearms evidence from an animal and the surrounding crime scene is also considered to explain to practitioners the importance of sending this evidence for further forensic examination and analysis.