I have a Ruger Mark IV Lite. I have been doing some work on it, William sights and Tandemkross Victory trigger. During the trigger upgrade I launched the bolt stop spring across the room. I contact Ruger support to purchase a new spring. The customer service person I spoke with was very nice and helpful. I told her that I lost the spring. I relayed the number I needed from the parts list. She did her research and confirmed the spring I needed. She looked me up in the system and verified my address. Then she thanked me for calling. I told her that I have my credit card number whenever she's ready. She said it was no charge. I thanked her and she thanked me. Just another reason Ruger is on my list of companies I will do business with.