NOT KNOWN FACTS ABOUT S&W 340PD

But I have lately obtained a M&P 9mm which has the identical situation with weak ejection. I have study that A few of these guns just "need to break in" and up to now I have fired approximately 250 rounds of ammo (various mfgs.I have a person on my model 85 that works better that I purchased new, but nevertheless is hard for making changes for some