Those harder bullets are meant to be driven at magnum velocities. Try h110, 2400, aa9, or similar magnum powders. It is my belief that fit is king. If your bullets are a snug fit in your cylinder throats, meaning you can push them through your throats with light finger pressure, you should be good at any velocity. If they will just fall through your throats, they may be too small. I cast and powdercoat all my bullets, and never make any harder than 12bhn. That said, all my bullets are optimally sized to my cylinder throats. The coating will make them a little more forgiving with respect to leading.
If all this sounds foreign to you, just load some up and try them. They may be fine. I would experiment and see what works. I wouldn’t load up a bunch until I know they will be good. For what it is worth, I find that softer bullets (12 bhn) work better on game at typical handgun velocities. Rifles require harder bullets. Worst case would be that you have to clean a little lead from your barrel. Shoot some then shine a light in your barrel, if they are leading clean your barrel and try something else.