Yes - I think I know where you're coming from, but technically speaking, .50 X 3-1/4" brass is available commercially, so it isn't a wildcat. Wildcats are those which the case is made from a different case, neither available as a standard item, nor can be formed by firing factory ammo in the new chamber.
: Although Sharps never chambered a straight 3-1/4" case, Shilo does, or did. I had a Shilo m74 Side hammer in .50x3-1/4". Mine was throated quite long, about 1/2", and due to that long seating, the case held 170gr. of 1F just as Elmer Keith said it would.
: Supper call, back later with some data for you. heh Heh