While it's not recommended, it's certainly been done before. There's an old topic I read about that on here and I believe the basic advice was if you already have one, to start with light loads and work up slowly. The 44 mag max pressure is 36000 psi, and the 30-30s is 42000. The sb1 frame isn't quite as strong as the sb2. Of course if you had to get it either way you'd probably be better off getting a different one on the sb2 frame, and it never hurts to have multiple frames if you've got multiple barrels... But "just" as a hypothetical, it "can" be done