So a woman shows up for a basic pistol course and her slide on her G19 isn't locking back on the last round. So I take the mag out, look at it, and everything looks okay. I put it in the gun (unloaded) and check the tension by pulling the slide back---doesn't lock. I disassemble the mag and this is what I see On the left is a normal G19 mag spring, right is hers. The impressive thing is the gun was functioning fine besides not locking the slide back on the last round. Any thoughts on how the heck that happened? Inside of the mag was pretty clean. Woman had no idea as it was her ex-husband's gun.