are noted by a dash number suffixed to the Model number (15-1, -2, -3). Over the years the Model 15 has been produced with several barrel lengths, with 4" (standard) and 2" (1964–1988) being the most common. In 1972 S&W released a stainless steel version as the Model 67. In 1997 the hammer and internal lockworks were modified from an on-the-hammer firing pin / internal hammer block to a floating firing pin / MIM flat hammer, and kept the hammer block that, unlike a transfer bar safety design, moves up with the trigger pull. The hammer hits a transfer bar, transferring the strike to the firing pin, while the block in a hammer block system moves down with the trigger pull, unblocking the hammer from the firing pin, allowing the hammer to strike the firing pin. These two safety systems work oppositely, but achieve the same goal of only allowing the gun to fire when the trigger is pulled all the way. The Model 15 was a popular sidearm for law enforcement and was the standard-issue sidearm of the U.S. Air Force Police from 1962 until 1992 when it was replaced by the Beretta M9 pistol. Production of the Model 15 was discontinued in 1999 when Smith & Wesson was purchased and reorganized, although a couple limited run "Heritage Series" models were released in 2001 and 2002. In 2011 Smith & Wesson re-introduced the Model 15 (15-10) under their Classics Revolvers line, newly machined, with a shrouded redesigned barrel, and a built-in trigger lock (located just above the cylinder release thumbpiece on the left side). Specifications Caliber: .38 S&W Special Capacity: 6 Barrel: 4” (standard configuration) Length overall: 9 1/8” With 4” barrel Weight loaded: 34 oz. With 4” barrel Sights: Front – 1/8” Baughman Quick Draw on plain ramp. Rear: S&W Micrometer Click Sight, adjustable for windage and elevation. Frame: square butt with grooved tangs Stocks: checked walnut service with S&W monograms Finish: S&W (CHROME) with sandblasting and serrations around sighting area to break up light reflections Trigger: S&W grooving with adjustable trigger stop Ammunition: .38 S&W Special, .38 S&W Special +P Engineering and production changes timeline As the K-38 Combat Masterpiece Revolver Model 15 evolved the following engineering and production changes were made: 1949, K-38 Combat Masterpiece introduced 1955, Delete upper sideplate screw 15, 1957 K-38 Combat Masterpiece continued as the Model 15; stamping of model number 15–1,