I can't answer your question because I didn't buy my 1911Sc to shoot a lot and have only run a few Federal 185-grain Hi-Shok hollow-point factory loads and some of my 185-grain cast bullet handloads through it and it tossed all the empty cases into my brass catcher's net. But I can offer a correction to your thinking about spring weights
Specifically, too light a spring will cause gun damage due to the slide being slammed back too hard. All a too-heavy spring might do it prevent the slide from traveling fully, which would cause failures to eject empty cases and feed new ones from the magazine.
In 1911s with internal extractors, tuning the gun's ejection habits usually is done by bending the extractor to change its tension so my first thought is that you might want to try changing the tension of the external extractor's spring. Fortunately, both of my S&W 1911s came out of their boxes "housebroken" so I have no first-hand experience with doing that. You might want to ask S&W if no better info comes from other posters.
Ed
