Glock won't lock to rear ...

[Basenshukai]

Well, that's essentially the problem I'm currently having. My Glock 19 has developed an issue with locking to the rear when the last round is expended. Originally, it did this about once every 30, or so rounds. I attributed this to cheap target ammo. Over the course of the last few months it's become too common. In fact, I decided to fire the regular ammo I carry for personal defense and still the same problem.

My glock has a new trigger and an extended magazine release. These two items were inserted into the gun about a week ago. The problem has occured for far longer than that. I'm gonna experiment with firing the gun with my thumb completely clear of the slide release, just in case I'm pressing this with my current grip (just thought of that today). Other than that, what else could it be? Any experts out there have any advice. Thanks.

BAS