from 1836 until 1839. Unlike later revolvers, a folding trigger was incorporated into the Colt Paterson. The trigger only became visible upon cocking the hammer. Colt would go on to make a series of improved revolvers. The Colt Walker, was a single-action revolver with a revolving cylinder holding six charges of black powder behind six bullets (typically .44 caliber lead balls). It was designed in 1846 as a collaboration between Captain Samuel Hamilton Walker and American firearms inventor Samuel Colt. The 1847 Colt Walker was the largest and most powerful black powder repeating handgun that was ever made. The Colt 1851 Navy Revolver is a cap and ball revolver that was designed by Samuel Colt between 1847 and 1850. The six-round .36 caliber Navy revolver was much lighter than the contemporary Colt Dragoon Revolvers developed from the .44 Walker Colt revolvers of 1847, which, given their size and weight, were generally carried in saddle holsters. It is an enlarged version of the .31 caliber Colt Pocket Percussion Revolvers, that evolved from the earlier Baby Dragoon and, like them, is a mechanically improved and simplified descendant of the 1836 Paterson revolver. As the factory designation implied, the Navy revolver was suitably sized for carrying in a belt holster. It became very popular in North America at the time of Western expansion. Colt's aggressive promotions distributed the Navy and his other revolvers across Europe, Asia, and Africa. The .36 caliber (.375–.380 inch) round lead ball weighs 80 grains and, at a velocity of 1,000 feet per second, is comparable to the modern .380 pistol cartridge in power. Loads consist of loose powder and ball or bullet, metallic foil cartridges (early), and combustible paper cartridges (Civil War era), all combinations being ignited by a fulminate percussion cap applied to the nipples at the rear of the chamber. The Colt Army Model 1860 is a 6-shot muzzle-loaded cap & ball .44-caliber single-action revolver used during the American Civil War made by Colt's Manufacturing Company. It was used as a side arm by cavalry, infantry, artillery troops, and naval forces. More than 200,000 were manufactured from 1860 through 1873. Colt's biggest customer was the US Government with more than 129,730 units being purchased and issued to the troops. The weapon was a single-action, six-shot weapon, accurate up to 75 to 100 yards, where the fixed sights were typically set when manufactured. The rear sight was