Foster slugs, or "rifled" slugs, will work well in your smoothbore with open chokes, Cylinder or Improved Cyl. would be best for accuracy, but Modified may also work.
Don't bother with the sabot slugs, they are designed for use in rifled bores, or with rifled choke tubes, and don't give good accuracy with smoothbores.
Also don't shoot anything in your shotgun with no choke tube in place. It will probably ding up the threads so you won't be able to get a tube screwed into it again. And don't shoot slugs or heavy loads of large shot, like buckshot, out of a very tight choke, Full or tighter. It may bulge the barrel, and will probably seize the threads so you can't get the tube out.
A Sims LimbSaver recoil pad may make it more enjoyable to shoot slugs, especially at the range where you'll be shooting several.
You'll get fair accuracy, especially at 60 yards or less, using your bead, but for greatest accuracy, and longer ranges, get some rifle sights made to attach to the rib or barrel. Hi-Viz, Williams, and other companies make them, sold commonly at Cabela's, Bass Pro Shops, Sportsman's Warehouse, and other sporting goods stores, sometimes even at Wal-Mart and K-Mart.
I find best results with Winchester or Federal slugs in my guns. They usually come in a box of five, fairly inexpensive, so get a box each of several brands, and take them to the range to see which your particular gun prefers. Then load up on those.
