I have shot 450 rds of Winchester 230 grn ball so far and no jams, malfunctions or broken parts of any kind. I use the factory mag, a Wilson 47D and a McCormick SS Shooting Star mag. All magazines function well. Sorry to hear others having magazine and/or feed problems. I always do a thorough field strip/cleaning after a range session. I'd like to suggest those having magazine problems, try using the above mention ammo.
I can buy it at the local Sports Authority for $10.99/box 50.