My two oldest Ruger GP100 revolving pistols were made during a time when Ruger still cared enough to machine “powder-eatin’” grooves, under the extractor. These grooves can provide a place for unburned powder particles, and other small debris, to accumulate, without causing harm, until the user can find the time to clean the weapon.
I already favor the GP100, anyway, as I have since the very early Nineties, due to the perfect fit, in grip dimensions, and trigger shape and position being perfectly “natural,” for my hands. My avatar image shows my first GP100. Yes, my finger is on the trigger, as I snapped that photo, in a series, with an iPhone, to show my firing grip, to include my finger placement on the trigger.
If the user’s requirements allow a single-action weapon to be a contender, the Ruger Blackhawk has fewer things that can break, and there is no extractor “star,” under which debris can accumulate.