You can use a smooth bore to shoot slugs and if your gun has screw in chokes then you will have to leave one in. Most guns will shoot better with inproved cylinder choke in but not all. My 1300 likes mod. and I have an old JC Higgins that has been kept around for the express purpose of deer hunting that is a full choke gun and will hit a four inch circle everytime at 100 yards which is very good for an old smooth bore without sights.