a KN serial number would indicate a gun that was manufactured in 1999. That being so, yes you can have another barrel fitted to. It does however require factory authorization to do it. Keep trying until you get them, I have never had a problem getting them on the phone (?). I am not a betting man but I would put a couple of bucks on the factory being willing to add a barrel to that frame. Good luck....<><.... :grin: ERROR-ERROR-ERROR-SORRY!!! Don't know where my head was (oops, maybe I do, let me bend over and look again!) I had a false thought in my drafty old head when I read the first post. For some reason I envisioned an H&R receiver carrying a barrel marked Marlin. I then looked at the second letter of the serial number prefix, "N", and leapt to the false assumption it was an H&R serial number prefix indicating a 1999 manufacture date. So Sorry to all (and embarassed also, but I won't delete the post, I'll just learn to live with the embarrasment....<><.... :oops: :oops: :oops: :oops: