Alphecca has more on the UN gun treaty, which includes

another means of registration by the back door AND trying to make things too expensive for people to deal with:
An especially costly potential regulation discussed at the conference last month would require gun makers to engrave sequential tracings on every one of some 3 billion bullets produced in the U.S. each year.

And that, [a gun manufacturer representative] said, would make guns more expensive for everyone.

“Manufacturers would have to pass on the cost to civilian customers.” Another controversial part of the treaty draft establishes a compensation fund for victims of gun violence, which would transfer money from countries that export weapons to countries that had suffered gun violence.
Not just manufacturers; every store that sells ammo would have to maintain logs of every box and who it was sold to; paperwork and time costs. As to that money transfer... Ah, 'social justice' by a different name. Chances they'd actually enforce this against, say, North Korea? 0. Chances of trying to force us? 100%. Because there's not a chance they'd actually try to get money from, say Belgium for Germany because some clown in G used a gun made in F to commit a crime; this is one more bit of 'you have succeeded so you owe the world' crap from the socialists at the UN and all their little friends.