The Schoenauer magazine works much the same as a roller bearing. The cartridges themselves act as the 'pin bearings', the walls of the magazine well as the outer race which maintains the proper clearance between cartridge and the 'star' rotor while the cartridges make their rotational journey around the spool's center.
The shape of the cartridge nose and overall length are crucial to maintaining clearance without binding, as the cartridge will become 'jacked' if too short or too narrow about 1/3 back from the tip as it falls into a void.
Here are (6.5X54) cartridges in a Schoenauer magazine, out of the firearm for display. Normally the magazine would only have cartridges loaded while in the arm, as otherwise there is nothing to hold them in place. When loaded (from above, best when aided with a 'stripper clip'), you can see how they are guided by the magazine well and the machined areas at the front and rear of the magazine's lower housing (below).