Only S&W marked holster is for a N frame revolver. My S&W N framed 624
with the 6.5" long barrel fits as though it was made for it. Even has a swivel to better allow different positions when shooting. Frank
I have a black duty style S&W holster that fits a 3" K frame. Not a drop or swivel, but the belt loop is sized to fit at least a 2" duty belt, probably bigger.
Take a moment and search the Gun Leather forum for information about Smith & Wesson brand holsters, you should be able to get answers to just about any questions you have.