I believe the government bought lots of Mosins from Remington and Westinghouse after the Bolshevik revolution prevented them from being sent to Russia.
These firms were the “too big to fail” of the time.
I seem to recall some of these were converted to 30-06 for training purposes...or maybe it was just something Bannerman did.
Sorry I can’t speak more definitively...I have only vague recollections of this haha.