The tax stamp is certainly coming..... maybe even for ammo.

Not pedantic, old bean, perceptive. (I have a pretty good handle on what I think and do regarding these transactions but like asking questions to test the waters, so to speak, and to see what I can learn from the folks talking around the campfire.)

That said, I am less sanguine than some about the restraint of various government agencies regarding private property, search and seizure, datamining, and grandfathering various types of firearms and ammunition. So I tend to err on the side of simple bill of sales rather than more official records.

And like others have commented regarding taxation/stamp tax, don't get me started....

As a revenue generator, it's already here. We've got a nominal tax (in the neighborhood of.05-.10$)applied on every box.

Yes, yes, but I'm thinking more along the lines of registration when purchasing. THis is the true purpose behind these "tax stamp" government legalized scams. You know, providing name, address, etc (and maybe even:
"reason for purchase ___________________________".

That's what I understood you meant. The basis for it is already in place. All they have to do is change what requires a stamp. I predict it will happen in the future just because have you ever heard of a government loosening regulations. Eventually it'll be just like marijuana. IIRC if you've got the right stamp, it's legal to grow. Thing is they don't issue the stamps.

I went hunting for the first time a year ago and my uncle gave me the gun that he let me use (a single shot .17). Great! I'm a gun owner. In an attempt to further my interest in guns he lent me an old bolt action .22; later asking if I would be willing to give him $100, or $100 worth of ammo and just keep it (a steal)... now I own two guns... Then at the end of last summer he said he'd like me to "try" a larger caliber (.243) again asking later if I'd just keep if and give him $150.
Of course I trust my uncle, but he does a lot of trading and buying and selling with his gun buddies and a rural gun "shop" (some guy's living room converted). I don't have any paper work for any of my guns. One was a gift and my payment for the other two was more symbolic than anything.
If LE ever had a question, I'm sure my uncle would identify himself as the owner before me, but as far as I know he doesn't know their complete history. Also, it might look a little weird having 3 rifles that were all "gifts".

Unless things have changes in the intervening years, I would not be worried about the "gift" issue. From age 6 on up I have been shooting and from 10 on up competitively. Many of the trap/skeet competitions awarded a firearm as overall first prize (usually a Remington 870 or 1100). have been gifted more of those firearms than I remember from relatives that had to sign for them because I was under age. I have since sold them to others AFTER asking an ATF fellow the regulations on said sales (hope he was right).

Also, no child in the US would start hunting if not for the gift of a firearm. Just keep track of where you got them and you should be good to go.

Disclaimer: I am not an attorney. In fact, I bailed on law school. I didn't even sleep at a Holiday Inn Express last night.

Um, last I saw, possession of a stolen firearm was juast as bad as claiming ownership. If you are caught with it, you are caught with it. If the cops go to your uncle and ask where the firearm is and he says you have it (not that he is ratting you out, but because they really are going to insist he tell them what happened to it), then you are implicated, and the chain of custody ends with you. I would, in that case, expect to be charged with receiving a stolen firearm, or worse.

Except for the language included in the criteria" "knowledge" (which can be substituted with "callous disregard" or interpreted by a jury as "should have known")..............

For example: a defesne to prosecution is "lack of knowledge" that the firearm was stolen. An innocent claim is the best defense, but even better yet is evidence that the buyer took reasonable steps to ensure the weapon was not stolen or otherwise involved in crime....as stated in previous posts.

That would be due diligence, which wouldn't be a necessarily good defense in a private gun sale/purchase where chain of custody wasn't established. If you don't know the source, then be suspicious. Still better to err on the side of caution I would think.

Most likely it is a non issue 99% of the time, but for me, it just doesn't seem to be worth the potential hassle that could come of it. One-off transfers wouldn't be bad, but if I am the third or fourth party out, I would start to get a bit paranoid, and be wanting that identification of transfer from the previous possessor handy should the need arise.

In some jurisdictions, it is just easier for the LEA to arrest you and leave it to the DA to deal with it. They can arrest you, charge you, take you to trial and you can be found not guilty, but you will still have a record (flag) with NCIC that could be a real problem with all future fiream purchases, etc. This admittedly is walking into the "What if..." realm a bit, but it can, and does happen.