A shotgun used for shotshells features a smoothbore barrelBarrel that does not have any lands and grooves (rifling), meaning that there is no riflingSpiraled lands and grooves inside a firearm's bore (usually rifles and handguns). Give the bullet a spin as it moves down the barrel and out toward the target, increasing accuracy.. When a shotshell is fired, all of the tiny round pelletsProjectiles found in a shotgun shell -- shot. travel down this smooth bore to the target. The degree of sphericity or roundness of each pellet determines how the pellets fly.