Yea, you can use any straight walled cartridge as long as it's 1.8 in case length or less. At least that's what I've been told.
Researching the Savage, lots of guys in MI have them and love it. Was at Cabela's today and got a couple different boxes of Hornady's for it. Wanted Remington Accutip, but no 20ga on the shelves.
The line for gun sales was crazy.