I just mounted a suppressor on my 15-22. The sound of the bolt is louder than the shot itself. Does anyone know where I can get a 15-22 recoil buffer to reduce the sound of the bolt cycling?

Could just stick a thin rubber bump pad on the black piece that's connected to the rails of the bolt. Correct me if I'm wrong, but isn't most of the sound coming from the bolt ejecting a spent round and slamming the chamber shut? I don't really see any way of silencing that without causing a malfunction. Guns will never be 100% silent unfortunately

No way around it without maybe some custom machining. Metal on Metal will always make noise. All silenced guns have loud actions unless they have been somehow customized.