Ruger Blackhawk in .30 carbine
I have one, but in blue. I wasn't aware they came in stainless.
When you go to the range to shoot it for the first time, a word of caution. Since the .30 Carbine round is a rifle round, the powder used is meant to be used in a longer barrel than your Ruger, not that a 16.5" Carbine barrel can be considered 'long'. Not all of the powder will be burned before the bullet leaves the barrel. You'll have one heck of a muzzle blast/flame ball. The first time I took the .30 Blackhawk to the indoor range the guy in the stall next to me came over and asked what in the hell I was shooting -- and I had been shooting full-house .357s before that!
Really though, the .30 carbine round out of your short (?) barrelled Ruger will be travelling about 1450fps. Considering it uses a 110gr bullet, that puts it in .38Spl to .38+P territory energy-wise. When you start thinking about how much .30 ammo costs compared to .38, and what a pain .30 ammo is to reload (Carbide dies are expensive for this caliber, bullet selection sucks...), you'll see why this particular chambering is not all that popular.
Anyway, have fun with your new toy!