Bore of a Shotgun

The bore of the shotgun barrel is smooth because rifling would spread the shot pattern too soon. The length of a shotgun barrel will affect the length of time the shot travels in a tight pattern after leaving the barrel. A longer barrel will normally allow the shot to travel straighter further than a shorter barrel (assuming the same choke and shot are used). Keeping your shotgun clean will also help your shot traveling where you aim them to go.