I have a couple of scoped shotguns, but they are rifled barrels, which can take advantage of the 4X scope's magnification. If I were using a smoothbore gun, I would stick with a non-magnifying device (red dot) or a very low power mag factor, maybe 2X at the most-or iron sights, which will give you what you need for the actual effective range you are going to get with the "rifled" slug.