Take a close look at your handgun barrel the next time you are cleaning it. Since we never clean loaded gun, it will have been carefully unloaded and the ammunition put away. As you check the bore to be sure you have done a proper job of removing the debris, take note of its spiral grooves. They weren’t always there.
These grooves were pressed, cut or hammered into place when the barrel was a smooth tube. This process is known as rifling the barrel and the end result is also called rifling, so the word is both a verb and a noun. Rifling induces a spinning motion to the bullet as it makes its speedy way down the barrel.
In the manufacturing process, the tool that creates the rifling puts (usually) five or six grooves into the smooth tube. The parts of the barrel that aren’t touched by the rifling tool are called lands. Therefore lands and grooves equal rifling, which spins projectiles and increases accuracy.