Famous for its rugged construction and lever-action breech mechanism that allowed the rifleman to fire a number of shots before having to reload: hence the term, "repeating rifle". The first model, the Model 1866, was nicknamed Yellow Boy because of its brass receiver. The Model 73 was much more popular than the 66 because of the steel frame which allowed it to take the newly designed and more potent centerfire .44 cailber cartridge. The 1873 is often referred to as The Gun That Won The West. The 1866 was only available in .44 caliber rimfire cartridge at first, and the more modern centerfire cartridges were added to the production line later. The Model 73 was available in centerfire .44, .38 , and .32 calibers. During its production run, from 1873 to 1919, about 720,000 pieces were made in the Connecticut factory. Its tubular magazine was located underneath the barrel. This non-firing version clearly demonstrates the workings of the lever-action loading system.