There was a semi-automatic .30 Carbine chambered pistol called the Kimball. It was produced in small numbers in the late 1950's, looked somewhat like a High Standard pistol, and it was, by all accounts, not a pistol that is safe for shooting.
Aww heck, I see bamaranger mentioned it first. Interesting pistol, but not for shooting.
Taurus made a double action revolver called the Raging Thirty -- but I've not yet actually seen one of these and I've often wondered if it was actually produced or just advertised. I think it would be fun.
I've got a Ruger Blackhawk.
Attention Brass rats and other reloaders: I really need .327 Federal Magnum brass, no lot size too small. Tell me what caliber you need and I'll see what I have to swap. PM me and we'll discuss.