The .36 Caliber Colt 1851 Navy Revolver is a cap and ball revolver designed by Samuel Colt. It was designed in 1847 and was produced until 1873 at which time fixed metallic cartridges were introduced.  An estimated 250,000 Navy Revolvers were produced. This revolver was Colt's first major success.  The Colt Navy revolver is a mechanically improved and simplified  descendant of the 1836 Patterson revolver, also produced by Colt. The revolver fires an 80 grain lead ball with a muzzle velocity of about 850 ft per second.  This is roughly comparable to a modern .380 pistol round. Firing the pistol required use of loose powder, the ball projectile, metallic foil cartridges and fulminate percussion caps applied to nipples at the rear of the cylinder.  Sights for aiming the pistol consisted of a front bead sight and a notch in the top of the hammer at the rear. Wild Bill Hickok  was known famously for having won a gun fight by a single shot from a Colt Navy Revolver at an estimated range of 75 yards.  

Note: Nathan Bedford Forrest, Robert E Lee and Wild Bill Hickok were famous users of this pistol