My JM 1894P has handled every hot load I've put through it, though at least in my rifle I could never get the 300 grainers to fly straight. In the process of having a 1:18 twist barrel put on it. It's my favorite levergun. Very light with that big hole in the barrel.
I like my 1894 in 357 as well but going from memory it wasn't all that much faster with factory-loaded 158's than the 44 was with factory loaded 240's. The 44 mag is also lighter.
They're both great.
