Interrupted threads on TD's made early on. Later ones used regular uninterrupted threads. Like most things Savage, that's probably not cast in stone. (A little extra screwing never hurt anyone anyway.) Any competent smith who knows his way around a lathe can fit a new barrel. A new tube with a 1-8 or 9 twist is something I'd like to try too.

"You can lead a man to logic, but you cannot make him think." Joe Harz
"Always certain, often right." Keith McCafferty