What year is a smith and Wesson k590922 pistol?

The letter K prefix to your serial number was assigned to revolvers made by Smith and Wesson from 1946-1970.These were given to the models 14,15,16,17,18,19,48,53,66,67,68.It should be noted that all K prefix frames were target frame revolvers.Your serial number indicates that your Smith and Wesson handgun was made in the year 1964.