Steal them.
The elites could hire a vast army of foreign terrorists, arm them to the teeth with APC's, automatic rifles, grenades, etc. They could hit every type of Federal FFL on the books (including 03 C&Rs, private collectors), and take their Forms 4473 and bound books at gunpoint. Once they have the addresses of every American gun owner listed there, they could invade each and every one of their homes, and steal their guns and ammo.
They wouldn't get far without the whole thing going down in flames, but they've got the money to try. They are a power unto themselves now. So, why don't they do this?
“The elites could hire a vast army of foreign terrorists, arm them to the teeth with APC’s, automatic rifles, grenades, etc.”
And no one would notice, correct? Gotta watch out for those concealable APC’s.
;^)