At first I was thinking “swear I’ve seen turkey loads with FC”.
Yes, they certainly need to expand their FC line, but I don’t think there’s really enough market to justify the expense of warehousing or distributing the loads. The market for 20ga #3 is nonexistent. Because of marketing, the only truly popular buck loads are 12ga 00 and #4, although #1 does seem to be coming into style with internet-backed demand in the last few years thanks to ballistics and pattern testing being shared online.
IMO 20ga buck is not really needed with FC (don’t take this as saying it shouldn’t be available or is inherently wrong). I’d wager most people using the subgauge with buck are doing so for HD, probably don’t even pattern their guns anyway, and are smaller shooters. FC isn’t necessary to make a 7yd shot across your house.
The only product line that comes to mind for actually making available odd size buck loads is Remington. Which who knows what the heck they’re going to actually make now, especially in this market. They were only basic loads at that. I think the recent dump of odd size R shells into the market was from the warehouse being unlocked after their bankruptcy/shutdown, or them burning up the last of their odd components to make room for more standard production of clay/dove, double aught, and slug loads. Of course anything will sell in this market, but this market demands the norm, for now.
Federal really needs to release the FC wad as a component, or even easier for their production lines, just sell one of the wad makers the rights and collect their royalties.