I got an M&P40c about a year ago and since then I have put about 6,000 rounds through it. When I first got it when shooting the slide would lock back when I still had rounds left in the mag. That would happen once or twice maybe every 200-300 rounds. So I didn't like it but it is the only gun I can conceal really well since my xd and 1911 are full size. And I got pretty fast at figuring out the malfunction and slingshot the slide to get it back up. But yesterday I went to the range and shot maybe 500 rounds through it and it locked back probably half the time and really made me mad. I have shot a friends m&p40c and never have that problem so I don't think it is me limp wristing or my grip but I was wondering could it be the slide lock spring? Should I contact S&W and see what they have to say or take it to a gunsmith and have them look at it?