This question has been asked before in previous threads.
I'll answer it again in the interest of those of you (us) who are interested in this conversion.
After taking measurements and inspecting my 1894C, the answer is a qualified "yes" with conditions:
1. Need modifications to the cartridge lifter, cartridge guides, ejection port, and possibly loading gate and loading port.
2. Gun should still feed, chamber, and fire all .38 Spl and .357 Mag loads, but with significantly reduced accuracy because of the long throat condition resulting in rechambering to .357 Max.
3. Advise against firing mixed batches of .38/.357 after firing .357 Max because of firing residue buildup in chamber and the much higher pressures of the .357 Max. A similar condition applies to firing .45 Colt in .454 Casull guns. Thorough chamber cleaning is advised before firing .357 Max.
4. .357 Max cases are much more expensive and harder to find than .38/.357. If the power is needed, why mot go to a bigger .35 cartridge?