922r is a parts counting scheme (See below) I dont want to be the defender of it, (I think its absurd)...
Yes it is geared toward the assembly, but inorder to modify you need to include "x" number of us parts (Or reduce the number of foreign parts) to the prescribed number (Depending on features) allowed. Hand guards are counted in 922....
Modifying an imported AK should be done carefully, by carefully I mean....read up on 922r yourself, proceed with caution (And a determination to vote for people who dont pass legislation such as this.
Then re-read the Constitution and see how "the right to keep and bear arms shall not be infringed...."Ponder.....and repeat. )
The Gun Control Act of 1968 (GCA), 18 U.S.C. Section 922®, specifically states
the following:
It shall be unlawful for any person to assemble from imported parts any
semiautomatic rifle or any shotgun which is identical to any rifle or shotgun
prohibited from importation under the Section 925(d)(3)...as not being
particularly suitable for or readily adaptable to sporting purposes...
Also, 27 C.F.R. Section 478.39 (formerly 178.39) states-
"...(a) No person shall assemble a semiautomatic rifle or any shotgun using more
than 10 of the imported parts listed in paragraph © of this section if the
assembled firearm is prohibited from importation under section 925(d)(3) as not
being particularly suitable for or readily adaptable to sporting purpose.....
( The provisions of this section shall not apply to:
(1) The assembly of such rifle or shotgun for sale or distribution by a
licensed manufacturer to the United States or any department or agency thereof
or to any State or any department, agency, or political subdivision thereof; or
(2) The assembly of such rifle or shotgun for the purposes of testing or
experimentation authorized by the Director under the provisions
of[§478.151(formerly 178.151)]; or (3) The repair of any rifle or shotgun which
had been imported into or assembled in the United States prior to November 30,
1990, or the replacement of any part of such firearm.
© For purposes of this section, the term imported parts [tabulated below]
are:
(1) Frames, receivers, receiver
castings, forgings, or castings.
(2) Barrels.
(3) Barrel extensions.
(4) Mounting blocks (trunnions).
(5) Muzzle attachments.
(6) Bolts.
(7) Bolt carriers.
(8) Operating rods.
(9) Gas pistons.
(10) Trigger housings.
(11) Triggers.
(12) Hammers.
(13) Sears.
(14) Disconnectors.
(15) Buttstocks.
(16) Pistol grips.
(17) Forearms, handguards.
(18) Magazine bodies.
(19) Followers.
(20) Floor plates.