Hopefully you can get your money back. What it will come down to is Visa arguing with Moneygram. I'm not sure a sticky with known scammers will do any good, because they usually scam a few people quickly then disappear when there's too much heat. The best way to fight scammers is to be extra careful when dealing with a private individual. Ask for specific pictures with a current newspaper in the photo, ask for a copy or a picture of the sellers drivers license, do a check on their FFL (although the site cannot validate an 03), use safe payment methods, etc. I'm sorry you got taken. $700 is a tough price to pay for a lesson learned. Hopefullu Visa can get you your money back.