You're not giving us too much info. The 65 is the stainless version of the Model 13, S&W's .357 M&P. Fixed sights, very reliable. There are quite a few surplus 4" barrel versions from P.D.s and armored car services. Yes, it's a K frame.
The 3" round butt is much in demand as a CCW weapon.These are my two, both -3s.