I'm not sure what exactly the problem is, and it has only happened about 3 times since I've had the weapon (about 2 years now). However, if I ever need to use it, thats 3 times to many. Today, I was towards the end of a clip, I had just shot a quick 3 round burst, and on my next trigger pull nothing happened. (I can't recall if I heard the firing pin click, but I don't think it did.) I thought maybe it was a slide lock issue, but when I pulled the slide back an unspent round flew out. Any ideas on why it didn't fire? I'd appreciate the input. Thanks.