So I bought a pair of ProMag magazines for my Ruger LC9 on eBay. Bad mistake. I immediately noticed that my slide was locking open with one round left in the magazine. Not just inconvenient, but extremely dangerous. What if someone just closed the slide without looking, then pulled the magazine from the now "empty" pistol? At first I didn't know whether it was the new magazines or the new Blazer ammo that was doing it. Last week I spent some time at the range testing. I put two Blazer cartridges in each of my three magazines. The Ruger magazine worked flawlessly. Both ProMag magazines exhibited the problem. I then tried all three magazines again with Winchester white box ammo. Same result. Close inspection reveals that when the problem occurs the last round is left in the magazine, slid forward about 1/4" (by recoil?), enough to cause the slide to lock open, as with an empty magazine. I'm going to see if I can make the ProMags work by strengthening the spring or some other tuning, but I really don't trust them, and I certainly wouldn't resell them to anyone. If I can't get them to work they will just be garbage. Anybody else got any suggestions? I bought these from a private seller on eBay last December and really didn't get a chance to try them out until this summer, so getting a refund is probably not an option.