In the late '70's, I bought a Model 25-2 second-hand. Couldn't resist. Still have it, still like it. I get good results with hardball but any cast bullets have so far been a minor disaster, with leading and keyholing. I've tried up to .454" with poor results. I can understand why. The chamber throats measure out at .456". Has anyone ever got a definitive answer about why Smith and Wesson would have bored the chamber throats so large?