I've read reports that sometimes rifled slugs seem to be "hit or miss" in cylinder bore 870's. I haven't fired any out of mine yet but do have some Federal Hydra Shocks...I want to be able to extend the range of my 870 express mag with 18" barrel. At longer distances, my pattern is kind of huge...so I'm hoping that the rifled slugs will add some effective distance to my 870 as well as packing a wallup...