Manufactured in 1954-1956. This revolver was produced on government contract for the U.S. Air Force, who designated it the Model 13 Aircrewmen and requested the revolvers be stamped "M13". They were intended for strategic bomber crews for use as survival weapons. Weight conscious, they were originally produced with a lightweight alloy frame and cylinder with a steel barrel. The model was rejected because of problems with the alloy cylinder with most destroyed by the government or S&W, making surviving examples rare and highly desirable. The top strap is marked "REVOLVER, LIGHTWEIGHT, M13". Back strap marked "PROPERTY OF U.S. AIR FORCE". The left side of the frame has a "P" proof mark. Serial number "C368839" is on the butt of the frame. The barrel is un-numbered. The six-shot alloy cylinder and extractor are numbered to different guns. The checkered grips have S&W medallions, with the right panel numbered to the gun. This revolver falls within the accepted Aircrewman serial range of C247000-C405363 ("The Standard Catalog of Smith & Wesson" by Supica and Nahas, pg. 147). Includes a black leather "USAF" marked holster with shoulder strap