Re: buying guns
Money Orders are like certified checks, they only guarantee the money is there, the post office will do nothing to get your goods if you get screwed unless you can prove its "Mail Fraud". Someone has to be advertising thru the mail, in this case it would be Internet Fraud a totally different animal. There are sites to explain about Internet Fraud and what actions can be taken if you get screwed in a transaction.
Collecting the goods, or getting the money back is not easy if a deal goes bad, unless you follow Buffalobob's suggestions.
My suggestion is if you don't feel good about the deal run away!
"A tie is as good as a loss, and no one remembers second place."