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If you have an aversion to the 5 shot revolver there is always the 2" 327 from Smith and Wesson. However that is an 8 shot, 357 Magnum revolver weighing in at 21.6 ounces.<<
I don't have aversions to any guns

and my most carried gun is a Model 640 no dash in a Sparks Summer Special 2. I find N frames to be too big and unbalanced for my taste.
The diameter of a J frame cylinder is approximately 1.3". The Colt D frame is about 1.4" and the S&W K frame is 1.45". Small differences but the Colt and the 640 carry/conceal better than the K frame. Some of that might be due to the K frame having a thicker frame than the other two.
I don't think anyone is building a 1.4" diameter 6 shot cylinder today, Charter's cylinders are 1.45 but their guns are light possibly because of at least partial alloy frames. And their frames might also be thinner than K frames, Rossi also, but I don't have measurements for their frames or cylinders.
I sometimes carry a 2" model 10. They run about 29 ounces. The standard magna grips are difficult for me to conceal. I find the thinnest and best grip to be the Pachmayr Compact Professional.
The original Model 12s had a thinner frame. I guess S&W recognized the advantage especially competing against the Detective Special.
My Detective Special is in good mechanical shape but carrying a blued gun next to the body in Florida leads to corrosion problems even with careful maintenance. So finding an alloy or stainless replacement would be nice, and that's the reason for the search.
Bill