Cha-Lee, I've run my 40 Pro with the same mag extensions but using the ISMI springs and stock followers with no nose dive issues using the same U-die I used with my EAA Limited loading. I'm only loading to 19/18 but did not have any feed issues (Zero 180gr JHP, Major) Is it possible that your recoil spring may be too light? I only ran for approx 100rnds before going to an STI platform but if there was even one nose dive issue I would have been disappointed since that is what drove me away from my Limited. I also never had any feed issues when I was running my 9mm Pro in limited minor with the same mag set up for approx 5K rnds, no issues. I think once you find what theproblem is, your gonna love the M&P!!!!!