I've killed more than I can count with cartridge revolvers over the years, but none with C&B. It's just on the "haven't got around to it yet" list, though. I did a whole bunch of experimenting (5-7 deer limit for most of those years) with calibers and loads in cartridge guns, getting down into and below that possible with your Ruger with perfect results. Look at the ballistics of the standard velocity loading for the 45 Colt or 44 Special for comparison. Both are outstanding on deer out to the 50 yards I've tried them. "Testing" a variety of 38 Special and 357 Mag loads for defensive use, I tried them on deer. The worst was the standard 38 Special round nose bullet. But put a flat nose bullet in it and be careful with your shot, and it did okay too. Just not as emphatic a killer as the 44 and 45.
I haven't shot any deer with 44 or 45 RB's at any velocity, so you'll have to draw your own conclusions. But with a conical I'd have no qualms about the Ruger. But just be darned sure of your shot.