I consider 150 yards to be my max with my Rem 1100 with Hastings barrel and Win. BRI sabots because of the trajectory. The gun is probably accurate well beyound that, but I don't like holding over a deer's back.
My ancient smoothbore Ithaca Deerslayer, on the other hand has about a 75 yard max range. So my experiance is pretty similar to what C130E has stated.