If rounds are sitting in the mag they should be held down by the cartridge interuppter, Actuating the bolt causes the interrupter to move aside and allow a single round to spring free of the others for feeding, the Interrupter is supposed to do away with rimlock, if the interupter is not releasing rounds as the bolt is cycled you have excessive tolerance between the bolt and the interrupter,
when this ctg interrupter works properly it shouldnt matter what way you stack ctg rims in the mag.
I'd suggest removing the interrupter and check it for Burrs or mabe Cosmoline gumming it up or is worn out or improperly installed.
This same type interrupter system also is used in the Winchester model 1895 leveraction rifle as well for the rimmed rounds in Box mag repeating rifle
With some studing you'll discover rimmed cartridge interrupter systems of diffrent types in all the early boltaction rifles.