The Winchester Model 1866 was a revolutionary design when it was first produced. It might not have been the first leaver action rifle, but it did give rise to the popularity of their design. At the time of the Model 1866’s introduction, single shot muzzle-loading rifles reigned supreme, and repeating rifles that used metallic cartridges were still considered a novelty. The Model 1866’s ability to fire over and over again without reloading gave it’s user a massive amount of firepower and a considerable advantage over those still using muzzle loading designs.