I have used S&W warranty on two occasions for two different guns. These issues were about 5 months apart. Both timed I received the auto respond e-mail very quickly but did not get the return FedEx e-mail for a week or so. I sent them in the next day and waited over 2 months on the first before I called CS and was told they were "working on the issue" they said it should be completed soon. The next day I got an e-mail from S&W saying it was fixed and would be returned soon. I got another e-mail a few days later saying it had been sent. Got it 2 days later, nearly 3 months in total.
The second issue started the same but this time I called CS after 2 weeks to check on it. I was told that it had been repaired and was waiting to be shipped. The CS could not say when that may be. I never got any additional e-mail from S&W but 5 days later it arrived via FedEx.
Frustrating but a bit faster the second time. I believe the first time I would have waited forever if I had not called to check on it. The second time CS said that the repair had been completed the previous week and was waiting to be shipped????
Good luck, hopefully it arrives back to you soon.