A S&W K-frame revolver is a fine machine indeed. The K-frame was originally built for .38 special though so, as mentioned, take it easy with the .357 loads. When you do fire .357s, stick with heavier bullets (140 gr and up).
That being said, they certainly aren't fragile guns and they are sought after.
"And I'm tellin' you son, well it ain't no fun, staring straight down a .44"