Ok, so forgive my newness, but here's my problem. My new 9mm HK p2000 V3 does not consistently lock the slide back on an empty mag. I've ran into the problem on both factory supplied magazines, and can't consistently duplicate the issue. I've gone through 300rds of Remington "Range Bucket" ammo, and have had no other problems. Mags seem to seat just fine, and I can't figure out what could be causing it. Any suggestions?