JBP, I've got two of these revolvers. As with all Rugers, they are built strong. The two rounds are very different, as you might expect. Love to shoot the .38-40 - easy on the recoil and a throwback to the cowboy days. The 10mm is a much different critter: sharp recoil.
Drawbacks: the .38-40 ammo is obscenely expensive, a problem I've solved by reloading. The cases are more expensive and kinda fragile. The 10mm ammo is expensive, although I reload that as well.
Obviously, with the single action you can't use moon clips so the round fits directly into the chamber. There is a problem in that the cylinders will "clip" brass off the end of the case as you shoot and you soon have difficultly chambering rounds. A simple brushing takes care of this.
Love the flexibility and "rareness" of this gun! By the way, I paid $350 NIB a year ago - it really appeared to have never been fired.