An episode of the War Machines series tracing firearms from early muskets through to the machine gun, using archive footage, battlefield photographs, and expert commentary to explain how each innovation changed the way armies fought. The film moves chronologically through key advances in loading mechanisms, ammunition, and rate of fire, showing how muzzle-loaded muskets requiring slow, exposed reloading gave way to breech-loading rifles and eventually to belt-fed machine guns capable of sustained automatic fire. Battlefield case studies illustrate how these changes altered tactics, from massed infantry lines to trench warfare, as weapons outpaced the strategies built around older ones. Archive combat footage and period imagery sit alongside narration that explains the engineering behind each leap forward. The episode treats the firearm as a case study in how necessity, competition, and industrial capacity drove weapons design across centuries, ending with the machine gun's role in making early twentieth century warfare vastly more lethal than anything that came before it.