If you are doing a private party transaction in the City of San Diego, you must have already completed the sale before entering the gun store. I was just told that there's a City ordinance that prohibits private sales inside of an FFLs facility. Once they become aware that the transfer is anything other than a "done deal" (one party examining the firearm, cash exchanging hands, etc.) they gotta refuse the transfer and toss you out. Meet somewhere else. Look the gun over, agree on a price, pay, etc. Then walk into the FFL and simply ask for the transfer. I don't know if this is only handguns, or all firearms. And this is a City ordinance, so FFLs outside of the City (East County, North County) do not, to my knowledge, have this restriction.