If it didn't do it to start with I can't see it being a feed ramp issue. If the ramp was smooth and bullets were feeding fine when new there should be no damage/rough spots on the feed ramp from normal use/cleaning/lubrication.
One thing that is a good idea, whether the magazines are dirty or not, is to disassemble the magazines, clean out any crud/lubrication inside them, degrease the outside and put a couple coats of good car wax on the metal surfaces inside and outside. Just like your car/truck. Clean them, put a coat of wax on, let it dry a few minutes (till it hazes over) and wipe the excess off. Then repeat.
The wax will protect the surfaces from rust and the inside will be slicker to help with loading/feeding and dust/dirt won't be so bad to stick to it or build up on it.
1sow recommended that last year when I expressed concern about how wet my P01/magazines got (sweat and rain and splash water from high pressure washing). It worked great. For the rest of the summer I'd come in the house, dry the pistol off, pull the mag and the spare mag out and just wipe them off with a dry paper towel. They'd shine like a new penny. Worked so well I even waxed up my new XD magazines last winter. They're stainless but stainless does corrode and they stay cleaner with wax on them.
Good luck with your pistol.
