No they don't use the same bullets. Marlin had a lot of trouble initially with folks using jacketed pistol bullets in the 444. 300 or 350 gr hardcasts are the way to go (if you can get them to shoot)
Best you can do with a 444 300 gr (and the twist is wrong) is almost 2100 fps
A 45-70 can 2500 or more and is not bordering on being obsolete.
