.45 ACP. Known as the "1950 .45 Military" before 1957. Introduced in 1951. Similar in appearance to the Model 21, except chambered for .45 Auto Rim or .45 ACP cartridge. Half-moon clips are used with the latter. Estimated that around 178 Model-marked guns were made between 1957-1966 in the serial range of S185000-S263000. Two Engineering changes. Values listed are speculative due to rarity.