Brownells sells a tool to help keep that one spring from launching itself into outer space. I put the Apex kit in my 340 M&P a couple of years ago. Reliable ignition for even the hardest primers and a much smoother action. J frames get a lot of heat for having only 5 rounds but they are far more likely to be carried than left at home. Of course we all know that OSA members all carry a full sized pistol with spare mag and a backup.