The M1911, also known as the Colt 1911 or Colt Government, is a single-action, recoil-operated semi-automatic handgun chambered in .45 ACP. Developed in the late 1890s by John Browning, it was designed to replace the revolvers then in use by the U.S. military. The M1911 features a 5" barrel and an overall length of 8.25", making it a full-sized pistol. Its operation is based on the recoil of the fired round, where the slide and barrel move backward together, cycling the action without the need for additional fasteners, aside from the grip screws. Over time, the design has seen minimal changes. The M1911A1, an updated version, introduced enhancements like a grip safety, sear disconnect, slide stop, half-cock notch, and manual safety. The Colt MK IV Series 70 improved accuracy with a redesigned barrel bushing, while the Series 80 added an internal firing pin safety. The modern Colt Government models, including the Colt 1991 Series, blend features of the original M1911A1 with updates like the Series 80 slide and improved internal mechanisms. These models, available in .45 ACP or .38 Super, continue to reflect the "mil-spec" design ethos, providing reliable performance at a competitive price point. The latest versions include both blued and stainless finishes, catering to contemporary preferences while maintaining the classic 1911 design.