Hey guys, just signed up after owning an s9 for a while now. Been shooting it and have had MANY FTE's, stovepipes and FTF's. I thought it was just a matter of time and breakin period. Today I went to the range and shot out of 1 of the original 10 rounders and used (3) 17 rounders, two of which are new. This outing produced more of the same and even worse a new problem. Slide failed to lock after final round several times. SMH. I have been using this weapon as my CW and this is making me lose confidence quickly. The problems seem to happen after the gun warms up from a few rounds. I plan on going back and taking notes on the mags and ammo used. Never really documented results before but after doing some research tonight I will try to pin point the problem with some info & tips I read here. Labeling the mags and figuring out if this slide lock issue is a mag problem. I'll check the springs and what kind are in there. I will do more research but this is not good. I have shot a good 400-550 rounds, possibly a little bit more. I shot the first JHP through it today also. Before I finish this post I would add that I REALLY LIKE this gun. The ergo on it, is amazing. Seriously it just feels great and the sights really help me get on target quickly and very accurately. Trigger is smooth as a babies booty. That said if it keeps giving me problems I will be very upset as I have already invested a good amount of money on it. Bought 3 extra mags, a custom holster and a few trips to the range and spent ammo. The way things are now, buying the ammo I have spent already will be tough and I have another new 9mm I need to break-in and learn.