X9...; Not so,really!
If you are looking for loaded ammo, you might find your choices a bit limited. If you are, then search for "Cowboy loads" for the Sharps, and similar 19th Century styles.
Most of us reload, and there are plenty of supplies. Generally they are regular stock items available at the normal basic prices for most reloading supplies.
Like I told Cyrille; Look down below to the BROW board, and to THE DARKSIDERS DEN.