I was investigating using my 20 gauge Weatherby Orion S x S this turkey season. I contacted Weatherby customer service to see if they had recommendations as to who has a suitable choke tube for their gun shooting TSS.
The following is their response :

"When using steel shot, or any shot similar to steel, such as TSS or Bismuth, you should only use stainless steel choke tubes with modified or more open chokes. You should not use steel shot with Extra Full, Full, or Improved Modified Chokes of any kind. "
Do any of you have this shotgun and tried TSS with factory or 3rd party choke tube successfully ?