I believe the Weatherby shotguns use the same threads and interchange with both Winchester and Mossberg shotguns. You can buy a tube, rifled or smooth, that should work in your shotgun.

There are a lot of choices available from different manufacturers but I do not think you would go wrong with Carlson.

Some slugs work well with rifled tubes, some with open (I/C, etc.) tubes.

Do not shoot with the choke tube removed from the barrel.