I have the 1894S 44 mag too. It likes Winchester White box. It also likes the Hornaday ammo but their cases are shorter. I am getting set up to load for it, then I will empty the Hornaday cases and move them on.
Thank you all! Steve, I already reload 44 Mag for my S&W 629 and so far they seem to work well in the 1894. I just got some 44 special cases today so I'm going to load those up with W231 and see how they work.