I have another opinion about non-documented gun sales. If I'm selling a gun, I usually offer to do whatever makes the purchaser happy. If they want a bill of sale, I'll gladly provide it to them, complete with my address and phone number. When I'm buying a gun, I want absolutely nothing. I'll gladly provide a quick look at my drivers license, so he knows it's a legal purchase, but I'd just as soon he forgot who I was as quickly as it usually happens. If I buy a gun, it isn't gonna be used nefariously, but I still desire no paperwork at all. If I want paperwork, I'll buy from a dealer. I have nothing to hide, but when they come around to collect our guns, I'd like to have a few they don't know about.
About half my guns are dealer purchases, which is OK, but the other half should be known to no one but me. When the collection comes, I don't intend to be the only one without one. I also stockpile ammo every chance I get. Can't be too careful.