The Winchester Model 1906 was designed as a more inexpensive companion to the popular Model 1890, the main differences being the 1906's flat shotgun-style butt plate and rounded barrel, as opposed to the 1890s crescent butt plate and octagon barrel. When the Model 1906 first became available, it was chambered exclusively for the .22 Short cartridge, however this was modified after serial number 113,000 (in the second year of production, 1908) when it was made to cycle .22 Long and .22 Long Rifle interchangeably in order to ensure the rifle's continued popularity There were three different variants produced by Winchester; the .22 Short Model, the Standard Model, and the Expert Model. Although production ended officially in 1932, a small number of Model 1906 rifles were built out of spare parts left in the factory until 1936. The last known serial number is 847,997.