I've never had the chance to work with Musk Ox. I can tell you about what I have worked with as far as true horns go. The River Buffalo that you can order through pen supply company's is easy to turn but it's bad about cracking after time. I've turned horns from cattle with no problems as well as Bison or American Buffalo. The trouble with the last two was that the horns are hollow except for the tips which wasn't enough to make a pen so I used what I could to make inlays. I would guess the Musk Ox would be like the Cattle and Bison. I'm curious to see what you come up with. Good Luck