Rifling in the Rifle or Handgun Bore
A bullet fired from a rifle or handgun has a spiral spin that keeps it point-first in flight, increasing accuracy and distance. This is achieved by the rifling inside the barrel, from which the rifle got its name. The barrel is thick and has spiraling grooves cut or pressed into the bore. The ridges of metal between the grooves are called lands. Together, the grooves and lands make up the “rifling.”
The bore of a rifle or handgun is grooved, which puts a spiral spin on the bullet for greater accuracy.
The bore of the typical shotgun barrel is smooth because rifling would spread the shot too soon. However, some shotgun barrels are rifled for shooting slugs and sabots. Also, there are "rifled" slugs and sabots, which should be used only in smooth-bore shotguns.