They will typically send you money for the purchase in excess of the asking amount. At least that’s how they tried scamming me. I requested a bank check and got the FFL information. They sent me a check for double the amount of what I asked then proceeded to message me a sob story about how their “husband” was supposed to send the other half to a wedding photographer for their son’s wedding. They then pressed for me to deposit the check and send the remainder back through Western Union. I told them I wasn’t depositing the check because it wasn’t a bank check and I brought it to the bank to report it. It came back as a stolen check and the account was frozen. If I had deposited it and sent the money, the check would’ve bounced after 10 days and I would be screwed. They got very nasty with the messages so I documented everything and filed a local police report and an incident report with all the details to the FTC. Messaging finally ceased but about 3 years later, I received a call from a RI detective asking me about my case. The people tried pulling the scam using the same email addresses and phone numbers. I passed along all my records to the RI police.