Colt M1878 Colt M1878 The Colt M1878 is a double-action revolver that was manufactured by Colt's Manufacturing Company from 1878 to 1907. It is often referred to as the "Frontier" or the "Double Action Army" revolver. A total of 51,210 Model 1878 revolvers were manufactured from 1878 to 1907, including 4,600 for the US Ordnance Department. These are known as the "Philippine" or "Alaskan" models. Samuel Colt experimented with double-action revolver systems, but he considered them to be unreliable. After Colt's patent expired in 1857, other manufacturers began producing double-action revolvers, but Colt's Manufacturing did not manufacture its own double-action revolver until
M1917 revolver and replace a range of 1890s-era .38 caliber Colt and Smith & Wesson revolvers that had demonstrated inadequate stopping power during the Philippine–American War. The Colt M1917 Revolver was essentially the same as the M1909 with a cylinder bored to take the .45 ACP cartridge and the half-moon clips to hold the rimless cartridges in position. In early Colt production revolvers, attempting to fire the .45 ACP without the half-moon clips was unreliable at best, as the cartridge could slip forward into the cylinder and away from the firing pin. Later production Colt M1917 revolvers had headspacing machined into the