There are 16 parts of an AK rifle that count for 922r
No more than 10 of these 16 parts may be imported when assembled into a rifle
So on a typical (stamped receiver) AK, five (or six with a muzzle device) of these 16 parts should be made in the USA when you build your own rifle

On a milled receiver AK47 you need to replace 4 parts (or 5 with a muzzle device)
(There isn’t a barrel trunion)

These regulations do not apply to building an AK pistol.
You can not have a stock or forward pistol grip on a pistol.

The 16 parts of an AK rifle that count for 922r
(1) Receiver*
(2) Barrel
(3) Trunnion
(4) Muzzle attachments(flash hiders, brakes, barrel extensions, barrel nuts)*
(5) Bolt
(6) Bolt carrier
(7) Gas piston*
(8) Trigger*
(9) Hammer*
(10) Disconnecter*
(11) Buttstock*
(12) Pistol grip*
(13) Forearm handguards*
(14) Magazine body
(15) Follower
(16) Floorplate

The parts in red are the most commonly available parts made in the U.S.A.