Just bought a new (extended)17-round x 40.cal magazine for my Berretta PX4-Storm. The plastic traveler that pushes the rounds up doesn't seem to be moving very smoothly. Sometimes when I pull out a round quickly, it will 'hesitate', I suspect it is just new and will break in, not defective. Should I load/unload it several times, or take it apart and oil it? or something else? NOTE: The magazine is made by M.D.S. in Italy. This is supposed to be the EXACT SAME part from the same factory as the official Beretta OEM mags. The only visible difference is the name on the side, and the price-tag ($20 vs. $50).