In the current situation....which many in the know say is not going away soon.... the game has changed. 20 Gauge offerings are out there. You can wait until the season and hope you find something, or you can get it now. Most likely you are going to have to pay dearly either way.
Here is your 20 gauge 5 and 6's. I bit the bullet and bought 250, which should last me a good while for hunting Pheasants. Two years ago a friend waited and paid $20 plus a box for the cheap stuff in Mitchell, SD and was glad to get it. Have close to enough target loads for practice, and even they are not as inexpensive as in the past. So if I'm still here next season I won't be scrambling around.
Gas alone for a Grouse trip and two trips to SD is a couple K. Factor in food, lodging, etc and shells are mostly, as a friend says, another bag on the Queen Mary.
It's out there...get it now or hope you can come hunting season. 2 3/4 and 3 inch.. 5,6,7,8's.
https://bossshotshells.com/shotshells/bismuth/?Per_Page=24&Sort_By=disp_order&gauge=20%20GA
