What are the metal ridges between the spiral grooves on the inside of a rifle barrel?

The metal ridges between the spiral grooves on the inside of a rifle barrel are called lands. They are part of the rifling, which imparts a spin to the bullet as it travels down the barrel, enhancing accuracy and stability in flight. The grooves are the recessed areas that help guide the bullet, while the lands engage the bullet, ensuring a tight fit and promoting a more consistent trajectory. Together, lands and grooves are essential for improving the performance of a firearm.