I purchased a new 10 rd mag with the plastic piece on the bottom of the mag at a gun show this past weekend. When I took it home to do the load and break in period I noticed after I loaded 8 rounds, the 9th and 10th seamed to depress the mag spring all the way and make the mag loose and spring not work, untill I would bang my hand on the bottom of the mag to jar loose the spring and it then shot up and locked the rounds. What do I do? I just bought it and it seems defective so do I have to send it in already? It also isn't feeding right when I pull the slide back to chamber a round it jams almost every time.