the small frame "New Vaquero.") Thompson Center Contender "Magnum" .45 Colt loadings can also be safely fired from any gun chambered in either the .454 Casull or .460 S&W Magnum cartridges, though proper feeding may be an issue in repeating rifles chambered for either the .454 or .460 as the OAL is significantly shorter. Modern rifles with strong actions (such as the Winchester Model 1894, Marlin Model 1894, and new clones of the Winchester Model 1892) chambered for the cartridge can safely handle the heavier loadings. Handloading Colt .45 revolvers made until early WWII had barrels with .454" groove diameters. After this diameters of .451–.452" were produced. Using .454" diameter bullets in the smaller barrels will work but will generate higher pressures. Cases used with .454" bullets may have to be full-length resized to work in newer guns. Speer handloading guidance states that the loads they show should be used only in handguns made specifically for modern smokeless powder. The loads mentioned in No. 10 reloading manual state that they do not exceed 15,000 psi. This is the equivalent of +P loading as normal pressure for the .45 Colt is 14,000 psi. In a section specifically titled "45 Colt for Ruger or Contender only" Speer makes reference to velocities up to 1300 feet per second with 200-grain bullets. They also state that pressures do not exceed 25,000 psi (CUP). This is well beyond a pressure that can destroy even modern guns chambered in .45 Colt with the exception of the large frame Ruger Blackhawk, Ruger Redhawk, Freedom Arms Models 83 and 97, and the Dan Wesson. Uses Colt began work on their 1873 Single Action Army Model in 1871. Sample cartridges submitted for Army tests were made by UMC, using the Benet cup primers; commercial ammunition used the Berdan-type primer, followed by the more common Boxer priming. Original UMC loads used a powder charge and bullet. This was reduced to of powder, and later, by the Army, to . The .45 Colt cartridge remains in use years after its introduction. It is used as a hunting load on animals the size of deer and black bear. Heavier handloads will take the same range of big game animals as the .44 Magnum. Several two-barrel derringers are sold that are chambered in .45 Colt, and some of these derringers can chamber a .410 bore shotgun shell without any modifications being required. Revolvers