This is an extremely rare example of an original U.S. Army Test Trials Colt Model 1909 semi-automatic military pistol chambered in 45 ACP. This model is the true transition/forerunner pistol between the Model 1907 semi-automatic and the eventual final design of the Model 1911 pistol and would certainly be a centerpiece of any highly advanced Colt semi-automatic pistol collection. This series of pistol is thoroughly discussed on pages 45-52 in the noted reference book, "Colt 45 Service Pistols Model 1911/1911A1" by Clawson, with this specific pistol noted on page 50 and 51 as being delivered by Frank Nichols and Eugene Reising for testing to Rock Island Arsenal in early March 1910 and then being sent for further testing to the Field Artillery School at Ft. Riley, Kansas, on March 9th. At both locations the tests that were conducted were completely successful. This series of pistol is also described on page 84-97 in the excellent book "U.S. Military Automatic Pistols" by Meadows and Ellis. In there it lists this specific pistol by serial number as having been returned to the Colt factory on March 14th with it eventually being released to Albert Foster Jr. and then sent to T. M. Townsend in August 1911. As noted in the write-up there were approximately 25 of this model ever manufactured in total, (serial numbered 0 to 22 and some unnumbered) which were submitted to the US Government for testing in early 1909. This pistol was a dramatic redesign over the previous Model 1907 pistol with the following improvements, with most of them still in use today on the M1911/A1 pistols: 1) it replaced the old two link barrel lock up system with a "single link" barrel system 2) improved disassembly method via the removable front barrel bushing and recoil spring/plunger assembly, 3) the magazine release button was redesigned and placed on the left side of the frame, 4) the grip safety was redesigned and improved, 5) the ejector and ejector port were also redesigned and improved, 6) a new method for retaining the firing pin was developed i.e. the firing pin stop plate, 7) the loaded cartridge indicator was eliminated and 8) the slide lock release was made an integral part of the link pin. However, it still retained the long, exposed extractor on the right side of the slide, and the grip safety lock plate was still positioned on the right side of the frame. Also, the barrel retained the full locking lugs on the breech end of the barrel. The left side of the slide is marked with the very early two-line/two-block markings of "PATENTED/APR. 20. 1897. SEPT. 9. 1902,DEC.19,1905" followed by "COLT'S PATENT FIRE ARMS MFG. CO./HARTFORD CT. with no Rampant Colt logo. The right side of the slide is marked "AUTOMATIC COLT/CALIBRE 45 RIMLESS SMOKELESS". The serial number "20" is located on the left side of the frame above the trigger guard bow, the underside edge of the left rail, the underside of the barrel in front of the barrel lug, the side of the ejector, and the back side of the slide lock. The top of the slide has the early small, oval front sight with the early round top rear sight. It has the later style short, checkered spur hammer with the half-cock notch. The grips have the full checkering with a small diamond pattern area around the grip screws. This beautiful pistol has the early Colt high-polish blue finish with the Colt niter blue finish on the trigger, extractor, grip screws and magazine release. Magazine absent. The accompanying factory letter lists this pistol with a 5 inch barrel in .45 caliber, blue finish, type of stocks not listed, and as a "New Model" when shipped to loan account, Vice President F.C. Nichols, Colt's Patent Fire-Arms Mfg. Co. on February 26, 1910, as part of a 6 gun lot.