My one and only contact with BATFE was the day I got a letter with a scary return address on it. I was at work and on opening it I was informed that Agent "X" wanted/instructed" me to call his office about a firearm which I had recently purchased.
Nearly wet myself ... but called and was informed that he was not currently available, but I left my contact information and was told he would get back to me.
Lunch that day was certainly quiet and I was not at all hungry, but I did dig out my information on this rifle. I was/am not an FFL dealer, but always kept records of my purchases ... just because.
Mid afternoon, Agent "X" called back and asked me a couple of questions about this purchase. It happened to be a M1903 Springfield sporter, the ones done in the 1950's ... a really nice fit into my other military and non-military M1903s. Did I now own serial number XXXXXXX?, Did I purchase this on line from XXXXXX? My answer was yes to both questions. Out of curiosity, I asked what this was all about, that is if he could or cared to talk to me about it.
The gist was that the on line seller had already been previously warned by BATFE that he was to cease and desist from selling non-antique firearms over the internet without a license. He just plain blew them off. At this point I was concerned that I'd lose my rifle ... the agent said not at all. They did not need to have the physical rifle for their case ... I had made a legal purchase from my end, having it shipped to my FFL dealer, where I had gone through the background check and did the 4473 thing.
I told him I was glad of this ... it hadn't cost me all that much, but it fit nicely into my collection. He was in agreement and we had a nice chat about how back in the day, nearly every town of reasonable size had at least one gunsmith and these guys often turned out some really sweet sporters, especially if you hung a nice Lyman scope or #48 aperture sight on them.
My guy was apparently a "gun guy" ... we must have talked guns for 15-20 minutes. I didn't feel bad because, paying my taxes helped pay his salary ... so I was kinda' just wasting some of my own money.
My FFL dealer's agent is also a decent sort, according to what he tells me. Certainly all business, but reasonable and fair. That's better than being a jerk, I suppose.