At top is a 1956 K-32 chambered in .32 S&W Long, which is the ancestor to the Model 16. Middle and bottom are 1989 Model 16-4's chambered in .32 H&R Magnum, which will also fire .32 S&W and .32 S&W Long. The K Frame .32's are my absolute favorite revolvers, if you can find one for sale do yourself a favor and buy it!