Quote Originally Posted by GhostHorse View Post
Is it possible that the chamber has worn to the point that heating is causing expansion (yes, I read and understood the possibility that heating would result in a smaller chamber, but if that were happening I'd expect feeding problems getting rounds into the chamber) so the brass flexes upon firing to seal, but it's flexing further than usual and can't spring back to shape after the bulled leaves the case?

Here's an interesting question; will rounds that haven't extracted well fit in the chamber of another 1911 that is working properly? I just took 10 fired cases that haven't been resized, and they slid into the chamber of one of my 1911s with no problem. I'd be curious to know if the cases from rounds fired in your problem gun would do the same in another 1911's chamber.
It could very well be the brass that is expanding. I never thought to take the spent brass and try it in another 1911. I'll have to try that when I can get to the range.