Not sure on break in, gun should run fine out of the box but I know some makers do recommend a break in period, one that come to mind is Les Baer, they recommend 500 rds I believe before a detailed cleaning. Of course LB's are tight as a frogs u-know-what out of the box. Oh yea and step away from the dremel, l think more feed ramps are messed up than improved by trying to fix something that isn't broke in the first place.
500 rounds sounds good to me haha. And the only reason I wanted to polish the feed ramp was due to problems I have heard with 1911's taking hollow points. Wouldn't have used a dremel, was just going to polish it by hand. But it probably would be a bad idea to try shooting hollow points out of it before dicking with it haha.