I found this particularly interesting because most discussions focus on the firearm, not the evolution of ammunition itself. This article does a solid job of tracing how advances in ammunition shaped firearm design and use over time, which is a piece of the history that often gets overlooked.
Firearm ammunition has been a fundamental component of both the evolution of firearms and the progression of military, law enforcement, and civilian practices throughout history. Ammunition is a versatile tool, an interface between the mechanics of firearms and the intended effects on targets. The history is intertwined with that of firearms, and influenced by advances in chemistry, metallurgy, military needs, and technological innovation.
The story begins with the discovery of gunpowder, which is a mixture of saltpeter (potassium nitrate), sulfur, and charcoal. The first recorded use was in China around the 9th century. The Chinese initially used the gunpowder for fireworks and explosives, but it quickly found its way into military applications, with the first firearm-like devices, known as hand cannons.
These hand cannons emerged during China’s 13th century, and were rudimentary in design, intended to hurl projectiles using the explosive force of the gunpowder. They were crude, consisting of simple metal tubes or barrels, and projectiles were often stone balls, iron pellets, or simple lead shots. The powder was manually loaded into the tube followed by the projectiles with a wadding to keep the charge in place. The ignition process was also rudimentary, with fire or a fuse being used to light the powder.
By Alan Chwick

