Got my first Glock. A 23 purchased through the blue label program. Put 400 rounds through it and so far it is flawless with one exception. I am right handed. If I hold it in my right hand and cock it to about 1:30 - 2 o'clock then firmly insert one of the magazines that came with it the slide will go forward and chamber a round. Only does it with one of the two magazines (it is reproducible). Doesn't happen with the weapon straight up and down. Weapon empty, empty magazine doesn't happen either. I don't see anything abnormal on the magazine. Not really a big deal, saves me from racking the slide. Just surprised me when it did it.