I would not take the gun back to the dealer as they are not responsible. You deserve an answer and restitution from the horses mouth. If the dealer refunds and sends the gun back to SW that is the end of the story. But what about he next guy whose rifle blows up. SW needs to know about it, investigate it, and fix the problem.

If the rebound was not in proper register, then the gun ought not have fired. It did, and that is bad dangerous.

I hold SW in high regard, and they need to know about what happened to diagnose the problem. On top of that they need to at least compensate for a worthless gun.