The U.S. Armed Forces did not order any M1911A1 pistols between 1925 and 1936. In November the Navy requisitioned 1580 new pistols while the number of new pistols in inventory or OS (Ordnance Stores) had fallen to 82.  The Ordnance office directed Springfield to order 1580 pistols from Colts Manufacturing Co. before July 1936.  This order would fulfill the Navy’s requisition, but allow the Ordnance stores to deplete through normal attrition.  This is hardly a comforting thought with war brewing in Europe.  Before the end of the year, Colts had received and delivered three orders totaling 2349 pistols.  All of the 1937 production pistols still had the “MODEL OF 1911 U.S. ARMY” slide designation.  On May 26, 1926 the official designation for the “New Model” pistol was changed to “Pistol, automatic, caliber .45, M1911A1” by approval of the chief of the Ordnance Technical Staff and the Ordnance Committee.  Drawings however were not approved showing the new designation until January 27^th 1938.  Consequently the 2349 pistols delivered in 1937 still retained the “Old Model” slide marking of  “MODEL OF 1911 U.S. ARMY” rather than the official marking of  “M1911A1 U.S. ARMY” that had been moved to the frame for 1938 and later production, and are also “Transition” pistols.  

The nomenclature “Transition” is not an official Army designation but is part of the vernacular of pistol collectors.  Hence the term is, to some extent, open to interpretation.  Barrels of 1937 produced pistols are believed to be marked "COLT 45 AUTO" on left side and a "P" proof mark on the left lug. The magazines are further believed to be two-tone and marked identically to the commercial magazines of the time with a “COLT .45 AUTO” on the bottom.  Normal commercial production at Colts numbered the slides to the frame serial number by adding a matching number underneath the firing pin stop plate.  Many pistols observed by collectors, made in the prewar years (1937 through 1941) appear to have slides with numbers that are mismatched by a few tens or hundreds of numbers.  This is thought to be a result of mass barracks cleaning of pistols and subsequent re-assembly of mismatched pistols.  A mismatched number will usually decrease the value of a pistol significantly.  The first pistols made in 1937 had neither a “P” mark on the frame or slide.  Sometime during 1937 production, (at about 711001) the “P” proof mark was added to the slide and frame.  Interestingly, Colts started 1937 production by marking pistols with their normal “Verified Proof” (VP in a triangle) in their normal commercial practice on the upper left trigger guard bow.  They did this despite WWI production military pistols and (1924 pistols) never having had the mark applied.   Workers at Colts apparently felt that their Verified proof was an adequate proof marking and did not initially apply the “P” proof.  Furthermore, when the “P” proof was added, Colts continued to apply the verified proof throughout WWII production. Reference Charles Clawsons “Colt .45 Service pistols”. 

Images courtesy the Karl Karash collection
All images on this page are copyrighted K. Karash