I'm surprised to hear that your Pietta shoots conicals better than RB's. The Lee 200 grn conicals I assume?
Is your's a Remington or Colt repro? Do you know if it has the 1:30" twist? I'm unfamiliar with older models, and my understanding is all of the newer models, minus the Shooter's Model, are the same.
I'm thinking that the 195C would possibly make an excellent medium game hunting bullet, and wish I had a chronograph to see just how fast they can be pushed.
The one thing that gives me pause is that with the long driving bands and increased weight in a small volume may push the pressures too high for a repro using the more energetic powders such as Olde Eynsford or Triple 7 which I use. I'm thinking I'd keep from loading more than what a RB could handle to be safer. I wish I had a way to know for sure if I could load a max charge with them though.