In answer to Dick Dastardly's original question, it very likely did fire some black powder rounds--perhaps even primarily black powder rounds.
Just because smokeless powder became available in the early to mid-1890s doesn't mean that black powder went away. Its appearance meant only that black powder was no longer the best available propellant for military use. Factory loaded black powder ammunition for nearly all of the cartridges originally designed for it remained available for many years. For example, the 1930 Winchester arms and ammunition catalog lists both black powder and smokeless powder factory cartridges for the .45 Colt, and virtually all the other older cartridges. The various Ideal Handbooks contained information about loading black powder cartridges as well as the smokeless variety at least through the 1920s. I've been told that black powder factory ammunition remained available and listed in various catalogues until the beginning of World War II (1939-1940). Winchester was still selling black powder loaded .22 rimfire ammunition as late as 1949