The Colt Model 1889 Navy Revolver,
in the later half of the 19th century, there were two common ways a metallic cartridge revolver could be loaded (with exceptions). The first was through a loading gate, which made loading and unloading a slow process, with each cartridge being loaded one at a time, and each empty casing being ejected one at a time. The other was the break top. The break top ejected all empty casings, and allowed for fast loading, however the mechanism often compromised the strength of the frame, and the ejection mechanism often failed, leaving the user to have to pick out stuck casings from a chamber or the mechanism itself.
Designed by William Mason and Carl J. Ehbets, the Model 1889 featured a new method; the swing out cylinder. When the user pressed a button (cylinder latch) below the trigger on the left hand side, the entire cylinder would drop out to the left. Pushing the cylinder pin ejected all spent casings from the cylinder, allowing for fast loading, especially with speed loaders. The Colt Model 1889 was the first common revolver with such a mechanism, although some uncommon revolvers had similar designs. It was a double action revolver, chambered in either .38 long colt, .38 short colt, or .41 long colt. While they were available commercially, they were most popularly known for being used by the US Navy, who used the revolver during the Boxer Rebellion, Spanish American War, and Philippine American War. A limited number were also purchased by the US Army. While a brilliant design, many in the Army believed the revolver to be under-powered, especially soldiers who fought native warriors in the Philippines, who were said to have been shot multiple times before going down. Thus around the turn of the century the Army reverted back to the Colt Model 1873 or other revolvers chambered in .45 caliber. The Colt Model 1889 would remain in service with the US Navy up to around World War I.