Buying or selling on Armslist is much like Craigslist, or any form of classified adds. Be smart about what you share. Meet some place public when ever possible. Don't invite a stranger to your house unless the item for sale can't easily be moved. Also, don't go alone to someone's home if you can avoid it. Most people are good but be smart about it.
I've seen that some communities have parking spaces near the police department designated for this sort of meeting to help folks remain safe but haven't made use of them personally. I've only met in public areas (parking lots or at gun shows) for any firearm related transaction with folks I don't personally know.
I use a bill of sale, when buying or selling a firearm, to document the transaction and establish change of ownership. I prefer to deal with folks who also have a CHL which indicates they are legally allowed to possess a firearm; at least they were legal when the license was issued. I take a picture of their license to go with the bill of sale. When scheduling the meeting I discuss the ID and bill of sale with them. Very rarely folks will back out at that time which is certainly their right to do so.
You mentioned your range as a location for the transfer. You could ask them, or other FFL, to perform a transfer which they might be open to, and expect to be paid for.
Of course all of the above is applicable to FTF sale. I have no experience with any remote deals on Armslist and wouldn't trust anyone other than an established dealer for that.