Visited the local Dicks today, and saw an 11-87 sps waterfowl for $649, but it only comes with one choke tube, and no sling. But Gander mountain has one exact same, with choke tubes, and sling for $849. but the main question is, the one at Dicks, has a sling swivel Built IN to the stock. not the usual swivel. does anyone know the difference other than that?