What is the purpose of rifling in a firearm barrel?

The purpose of rifling in a firearm barrel is to impart spin to the bullet when it is fired. This is achieved through the helical grooves cut into the barrel's interior. When the bullet travels through the barrel, these grooves grab onto the bullet and rotate it around its longitudinal axis. The spin stabilizes the bullet in flight, which helps maintain its trajectory and improve accuracy over longer distances. Without rifling, bullets would tumble in flight and lose accuracy, making rifled barrels essential for precision shooting.

Increasing the speed of the bullet, reducing recoil, and enhancing accuracy by adjusting the sights are important factors in overall firearm performance but are not directly related to the function of rifling itself. Thus, the primary role of rifling centers on creating the necessary spin for accurate projectile flight.