POTD: Colt Model 1907 Military #15 – Birth of the .45 ACP
Sam.S 06.11.25
Welcome to today’s Photo of the Day! This Colt Model 1907 Military pistol represents one of the most pivotal moments in American firearms history—the birth of the legendary .45 ACP cartridge and the evolutionary step that led directly to the iconic M1911. Serial number 15 is one of only 205 ever manufactured and just 66 known to survive today. Produced in early 1908 for U.S. Army field trials, this pistol was among 200 delivered to Springfield Armory in March 1908 for testing with cavalry units. The trials were brutal by design—the Army needed a sidearm that could reliably stop determined opponents, leading to the development of the .45 ACP cartridge specifically for this pistol.
The Model 1907 introduced several features that would become standard on the M1911: the spur hammer design, modified ejection port, externally visible chamber indicator, and the distinctive grip safety with spur. The inspector’s initials “K.M.” (Major Kenneth Morton) on the trigger guard bow confirm this pistol’s participation in the official trials process. What makes this pistol historically significant is its role in solving the “stopping power problem” that plagued American forces in the Philippines. The inadequate .38 caliber revolvers then in service led to the Army’s search for a more powerful cartridge, ultimately resulting in the .45 ACP—a round that would serve American forces for over a century.
Most trial pistols were either destroyed during testing or lost to subsequent military service, making survivors like number 15 extraordinarily rare. This pistol bridges the gap between the black powder era and modern automatic pistol design, representing John Moses Browning’s genius in creating a platform so fundamentally sound that its descendants remain in service today.
“U.S. Army Test Trials SN 15 Colt 1907 Pistol with Case and Ammo.” Rock Island Auction Company, https://www.rockislandauction.com/detail/4094/3369/us-army-test-trials-sn-15-colt-1907-pistol-with-case-and-ammo. Accessed 9 June 2025.
