Re: 1911 Magazine Question
There might be something very wrong about using a magazine longer than what the gun is made for. I once did that with a 10 round magazine in a standard M1911A1. I inserted the magazine and smacked it with the palm of my hand to make sure it seated, then tried to release the slide. The slide wouldn't move forward. When I tried to eject the magazine, it wouldn't come out. It took me ten minutes to get that magazine out. And this was in the middle of a pin shoot, so folks were unhappy. But I couldn't leave the firing point with a loaded gun, and had to keep it pointed down range, not ideal working conditions.
What happened was that the magazine had no stop and of course, the floorplate was well below the pistol grip. So the magazine went in too far and wedged itself onto the slide stop. The slide stop was forced upward, and would not move. And of course, with the slide fully to the rear the slide stop wouldn't come out so I couldn't disassemble the gun.
Lesson learned. I tossed that magazine and bought a couple with the stop welded to the front to substitute for the floorplate. They worked fine.
It is easy to tell that story on myself and laugh because it happened on a range. Not at all funny had it happened in a less benign environment.