I have a Shield .45 that had the same problem. Let me suggest one other thing that you can try. It is simple and easy to do, and it has eliminated failures to feed with my Shield: Get some light-to-medium car polish, and lightly polish the lower feed ramp and the vertical wall below it (that's where the bullet tip is hanging up). Leave your Dremel in the box and do it by hand. I rub in a tiny amount of polish with a Q-tip, and buff it off with a cleaning patch. I do this with every cleaning, and I clean after every range session. Since I started this polishing routine, I have shot 1,000 rounds with zero failures to feed. And that is with the old-style followers. I'm guessing that this works because the smoother, slicker lower feed ramp area allows the bullet tips to slide by.
Good Luck!