RE: Rifled or smooth?
A rifled barrel with saboted slugs will give you 150-200 yd. accuracy. A good smooth bore is maybe a 75-100 yd accurate gun. There may be exceptions, but thet's the norm. Rifled barrels are designed to shoot saboted slugs. Although you could shoot regular lead slugs through them, I suspect they wouldn't have the accuracy or range as the sabots.