Which term describes the explosive material that pushes the bullet out of the casing?

The term that describes the explosive material that propels the bullet out of the casing is "powder." In firearms, this powder is typically a type of gunpowder, which consists of a chemical mixture that ignites when struck by the primer. Once ignited, the powder rapidly expands and generates a high-pressure gas that forces the bullet down the barrel of the firearm.

This process is fundamental to how a firearm operates, as the proper functioning of the cartridge relies on the chemical reaction of the powder to create enough pressure to move the bullet effectively. The casing holds all the components together, the bullet is the projectile that exits the barrel, and the primer serves the purpose of igniting the powder when the firing pin strikes it. Understanding the role of each component is crucial for safe handling and usage of firearms.