OK, what did I do wrong? I took my new 1911 E-series 45 ACP to the range for the second time. Everything worked well on the first range trip but today, the slide stop pin popped out twice while I was firing. Before each trip I had cleaned the weapon and I've tried to follow the directions in the manual and those I've seen on line. I'm figuring I did something wrong but don't know what it might be. Any ideas on what I might have done to cause this to happen? I cleaned it when I got home and have everything back together, but don't want to have this happen again. Thanks.