I own an M&P 340, J frame. Somehow, somewhere I lost the cylinder release button. I contacted S&W and inquired how to get replacement parts, and how much it would cost. The next day, I received an email from S&W saying, Thank you for contacting S&W. An order has been generated for the parts you requested at no charge to you. Expect 4-6 weeks for delivery. It's been about a month and my parts arrived today. Everything is mounted and the gun is at 100% again. Thank you Smith and Wesson for outstanding customer service.