I haven't seen the movie, but just about the only bolt-action with an under-barrel tubular mag being produced in the US at that time was the Remington-Keene.
http://www.19thcenturyweapons.com/507/keenesport.html
That said, it's more likely the used a cut-down European military weapon, most likely a German Mauser 1871/84 or a Swiss Vetterli, both of which were at one time popular in the US for use as sporters.