Considering buying a cheap J-Frame as a tackle box gun, but more for use as a holster mold (I don't cheap out on carry guns: Colt, Sig, Walther, Kahr). Looks like I can get a blued Taurus for $265, which isn't much more than paying $60+ for a blue training gun. My question for J-Frame aficionados here, is what constitutes a J-Frame? Is it any 2" barrel revolver? Is it only 5-shot cylinders? Are there significant differences between brands? From what I understand, an LCR will not fit a J-Frame holster and vice versa. Is this the same with the new Colt Cobra? Thanks! Any insight is helpful.