If your feed path includes the cartridge having to make a layover or buy a bus transfer to get from the magazine to the chamber, rather than taking a direct flight, you have not gamed out the simplest solution to the problem.
And before you hit me with "But Hiram Maxim...!", he died when ships and planes still had reciprocating engines and had to inefficiently waste energy yanking pistons to a halt and hauling them back to the starting point.
