The non-registered .357 revolvers are much more rare than their Registered Magnum model counterparts with only about 1,400 manufactured compared to about 5,400 Registered Magnums. The accompanying factory letter states the revolver was shipped on May 8, 1940 and delivered to E.K. Tryon Co. of Philadelphia, Pennsylvania with a 6 1/2 inch barrel, blue finish, and checkered Magna grips. This was a single gun shipment billed at the wholesale price of $35.45. The revolver is fitted with a rare Keith-King long-range front blade sight (a tri-level gold bar style designed by Elmer Keith) and an adjustable white outlined notch rear sight. A legend in the gun community, Elmer Keith (1899-1984) had a long and highly successful partnership with S&W. In 1934, Douglas Wesson of Smith & Wesson teamed up with Phil Sharpe and Keith to develop a new cartridge to compete with Colt's .38 Super Automatic. Taking full advantage of stronger revolver frames available by the 1920s, such as the .38-44, Keith was instrumental in hand loading a .38 Special cartridge far beyond its accepted limits. The result was the .357 Magnum, which was first introduced on the S&W Registered .357 Magnum Revolver, the most powerful handgun at the time. The high velocity cartridge quickly became a favorite caliber for law enforcement and a new breed of big game handgun hunters. The .357 is generally credited for starting the "Magnum Era," a period of time when larger calibers dominated the firearms market. Keith went on to develop the .44 Magnum and .41 Magnum. The development of the .44 Magnum started as a joint venture between Smith & Wesson and Remington Arms Co. with Keith being the most outspoken advocate for such a big bore handgun cartridge. His long-range front tri-level sight allowed for varying elevation holds to compensate for bullet drop trajectory. Matching serial numbers on the butt, right grip panel, cylinder, and ejector shroud. Provenance: The Dave Ballantyne Collection