I have had a back order for Federal Law Enforcement #1 Buck Flite Control shells since August. I imagine there are others who have been waiting longer.
I was able to purchase Remington #1 Buck and Winchester #1 Buck through Midway. Also found a private seller in Arizona with Federal #1 Buck, but he was not willing to ship.
These seem to be difficult to obtain. I have inquired through retailers, wholesalers and the manufacturer. No one is willing to speculate as to when this product might be available. ATK (parent company of Federal Premium) simply says that they are making it, and it sells out quickly.
To the best of my knowledge, Federal does not offer any other 12 ga 2 3/4 inch shells in #1 Buck.