Hi. A short time ago, I did a little reading about the Hodgdon Superformance powders. Hornady lists quite a few different calibers of loaded factory ammo with the Superformance label.
Several have questioned how the lone Superformance powder from Hodgdon could be used in such a wide range of calibers.
The recent issue of Shooting Times includes a discussion with Dave Emary of Hodgdon who explains that the powder used in the .17 Hornet is a BLEND of the THREE Superformance powders developed by St. Marks Powder company.

Ah HA!! So, even though there are 3 Superformance powders, there is only one available. Finally makes sense.

ron