I just bought my first Glock and my first choice was the Model 36. It is NIB. I'm new to the pistol and I must say I love it. I've fired 100 rounds of Winchester FMJ so far and have had no problems. I have 6 mags. Two came with the pistol and four were purchased at CDNN. All are factory mags. The mags that I got from CDNN have the number 1725 on the bottom. The mags that came with the pistol have no numbers at all. I've noticed the plastic separating near the tip of the mag. These are the factory Glock mags marked 1725 that I got from CDNN. The piece had broken off and I lightly filed it smooth. Is this normal for Glock mags or should I be concerned? I have two mags like the one pictured on the right and another looks like it is separating from the metal also. Should I send these back or is this just normal? thanks.