Welcome to the forum, Unloaded Open Carry, UOC. Ammo on person, not concealed,mag holster OK, not in pocket. See http://www.californiaopencarry.org for a variety of docs you can download and read. Check out the newbie forum here for more.
ETA: little clarification, loose ammo OK in pocket, loaded mags cannot be concealed. speed loaders in pocket or pouch OK also.