Rifling refers to the spiral grooves cut into the interior of a firearm's barrel. These grooves cause the bullet to spin as it travels down the barrel, which stabilizes its flight and improves accuracy. The design of the rifling can vary, affecting how the bullet behaves in the air. The process of creating rifling involves precision machining, and it is a key feature in many firearms, including rifles and handguns. The effectiveness of rifling is one reason why firearms can achieve greater distances and more precise targeting compared to smoothbore weapons.