I am new to guns and recently purchased a new mod 2. 40 s&w. While going through the first 200 rounds at the range the other day, about 4 or 5 times, the slide lock engaged before my magazine was empty and my thumb was not touching the lock. I hope that this will fix itself as the gun breaks itself in. I also noticed that the magazine springs are extra stiff. Has anyone else experienced this? other than that, I love my new handgun.