What is studied under internal ballistics?

Studying internal ballistics focuses on the processes that occur within a firearm from the moment the cartridge is ignited until the projectile exits the barrel. This includes analyzing the ignition of the propellant, the pressure buildup within the chamber, and the acceleration of the projectile as it travels down the barrel. Understanding these factors is crucial for firearm operation, as it directly affects the velocity and stability of the bullet.

While the other options pertain to relevant aspects of shooting and ballistics—such as the influence of environmental conditions on a projectile's flight path or the design characteristics of firearms—they do not define internal ballistics. Internal ballistics is exclusively concerned with what happens within the firearm itself during the firing sequence, making it a vital area of study for optimizing firearm performance and accuracy.