The .25-25 Stevens was an American centerfire rifle cartridge.
Designed by Capt. W. L. Carpenter, 9th U.S. Infantry, in 1895, the .25-25 Stevens was the company's first straight-cased cartridge. It would be used in Stevens' single shot Model 44, as well as the Model 44½ rifles, which first went on sale in 1903. In addition, it was available in the Remington-Hepburn target rifle.
While the .25-25 was popular, the .25-21 offered "practically the same performance and was a little cleaner shooting." It also suffered a "freakish" appearance, due to its length to diameter ratio. It was also found the usual 20 or 21 gr (1.30 or 1.36 g) black powder charge of the shorter, bottlenecked. 25-21 offered "practically the same ballistics" as 24 or 25 gr (1.56 or 1.62 g) in the .25-25.
The switch to smokeless powder only exacerbated the problem, due to the small charge. To cure this, handloaders use a mix of 3 to 5 gr (0.19 to 0.32 g) of bulk shotgun powder and 18 to 20 gr (1.2 to 1.3 g) of black powder, with bullets of between 60 to 86 gr (3.9 to 5.6 g).