Did no one notice the gouge in the land (and groove) at 9:00 in the barrel? And read the OPs post! New gun, not used!

I don't have an explanation or even a guess as to what it is, but definitely looks like scaly rust!

To OP, call S&W Monday morning, 800-331-0852, and arrange to send it back to the factory, that is where it needs to go. Don't forget to mention the gouge in the rifling too.

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Gunsmithing since 1961