Another option is the mag does not fully seat because the butt of the pistol is too long. I have a CT380 where the mag would not fully seat, the base of the front of the mag would bottom out on the polymer butt in the front. I tried numerous mags of mine and also several friends mags. It would bind the mag because the mag release would not go fully into the mag, which also made the release button almost impossible to push in to release the mag. On my other Kahrs there is a small gap between the mag and butt of the pistol, the CT mag was right up the the butt with no gap. I just used a fine file to remove some of the plastic on the front base of the butt. That solved my problem!