.32 Short Colt or S&W, light loads, and wear safety glasses ALWAYS!
Seriously. Reline it to .22. No matter how old it is, it has to be over .33 cal to be considered an antique. If it's gonna be registered, it might as well be usable.
Stick to standard velocity loads, too. The whole load on those is taken on the two screws that hold the innards in. They are not fully supported all the way across the inside of the action, and can flex a bit.
I like the old Favorites, they are not really strong actions, though.
Edit: Ironnose, did you make the pins any larger in diameter? That would make a huge difference.
Cheers
Trev