A Gizmodo article discusses the smell of the moon:
One of the things I loved about the AMNH's Beyond Planet Earth exhibition was a seemingly gimmicky, but quite surprising device: a machine that allows you to sniff what the Moon smells like! It was... weird.
Apollo 16's Charlie Duke and Apollo 17's Gene Cernan described the smell as "spent gunpowder". Duke said it was really strong. Talking to Mission Control, Cernan pointed out that it "smells like someone just fired a carbine in here", referring to the Lunar Module.
In any case, you have to try it yourself. You can visit Beyond Planet Earth: The Future of Space Exploration at the American Museum of Natural History in New York.
Or, I suppose, you could just fire a carbine.