is there a fix for this...i have 3 mags, 2 6 rounders and 1 7 rounder for my cm9. when i insert and empty 6 rounder i cant get the slide to lock open when racking it. when i insert the 7 rounder it locks open easy.

on occasion i can get the slide to lock open with a 6 round mag, but as soon as i drop the mag out the slide slams closed...