eeeeyuck, 922r, it gets really confusing. The short answer to your changing the handguard question is yes, that puts you into the 10 parts or less game with 922r. Here is the list of parts the ATF counts for 922r on a SKS:
1. Receiver
2. Barrel
3. Bolt
4. Bolt carrier
5. Gas piston
6. Trigger housing
7. Trigger
8. Hammer
9. Sear
10. Disconnector
11. Stock
12. Handguard
13. Magazine body
14. Follower
15. Muzzle device (Yugos only for their grenade launcher)
If you swap out any of those you have to play the 10 or less game. Note that the magazine on a SKS only has two parts, a body and follower, no separate floor plate. Tapco says their mags replace three 922r parts but that's not true on a regular SKS because there are only two mag parts to begin with. Adding extra American made parts that are not on the list does nothing to reduce the foreign parts count, it's not a percentage game.
On my old SKS-M I sent my trigger group out to Murray's gunsmithing and he replaced the hammer, sear and trigger with American made parts and did a trigger job which made a typical kinda rough SKS trigger silky smooth and nice. You can also buy those parts from him and do it yourself. I do not think that affects C&R but I'm not sure. My work PC won't let me link to Murray's so just look up Murray's Guns and you will find him.
The gas piston is the other easy part to swap out beside the handguard. Tapco used to make them and I think they may have resumed production now but they are pricey. Try this guy instead (but he might be out of stock right now)
http://www.cncwarrior.com/SKS-Gas-Piston-p/23152.htm You can also look on eBay or Gun Broker, just make sure they have USA or made in USA on them somewhere.
On mine I did the hammer/trigger/sear, handguard and gas piston. Since it is a SKS-M I needed to replace 5 parts instead of 4 because it uses AK mags which do have 3 mag parts because the floor plate is separate from the body. I didn't want to rely on mag parts for my parts count because I had Chinese mags that worked great so my parts count is fine no matter what my mags are. I may still replace the followers and/or floor plates because my handguard isn't stamped with USA or Made in USA. I have the package in my range bag which says Made in USA but that's a tad bit of a gray area.
As others have said I know of nobody who has ever been jammed up on 922r alone but if you get caught doing something else and they want an ad-on charge they will have a good one. As you also pointed out, the rules are probably going to be enforced more and more. Not sure if that will ever get all the way to 922r but why mess around with it when it's easy to avoid with parts that will make the gun better anyway? I know it's a SKS and will never be anything more but the hammer/trigger/sear with trigger job is well worth it if you want to really enjoy shooting it.
Here is a great link to SKS legal issues including 922r and C&R.
http://www.victorinc.com/SKS-FAQ.html#_Toc322267330
NOTE: 922r is different from any state or federal assault weapons bans. It has to do with the import, manufacture or assembly of non-sporting rifles, not ownership or sale as the AWBs deal with. So 922r applies to all firearms, even pre-ban ones. Once you start swapping our parts you are technically assembling the gun at that point in time, not back in 1993. That is my understanding anyway and how the SKS experts I learned from always interpreted it. I'm not a lawyer or ATF agent so if you want to roll the dice with claiming a pre-ban gun isn't subject to 922r be my guest but I think you would be wrong.
Some relevant excerpts from the link I provided to Victorinc:
Can’t I just modify an SKS Carbine I already own, after all it’s already been imported?
Title 18 USC § 922(r) prohibits “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 Title 18 USC § 925(d)(3).”
Put another way, it is illegal for anyone to assemble a semiautomatic rifle or shotgun domestically that would be prohibited from import were import attempted. The only way to know
for sure if a particular configuration is legal is to
write ATF and ask. Don’t be bashful—ATF has said that they will not publish a list because anyone can write them and ask if a particular configuration is legal.
Remember that Title 18 USC § 922(r) made it illegal to build any firearm prohibited from importation under Title 18 USC § 925(d)(3). See the explanation of “identical”.
My SKS is “pre-ban”, can’t I do whatever I want to it?
It is not legal to add a particular feature to a pre-ban SKS Carbine. One could have added it before the ban. If the rifle did not have the feature on the date the ban became effective, adding it afterwards would be illegally assembly of a banned firearm. A banned feature may be repaired, but cannot be added to a firearm.
The May, 1994
American Rifleman magazine featured an article on the subject which quoted Edward M. Owen, Jr., chief of the BATF Firearms Technology Branch, as writing:
On Nov. 29, 1990, the Congress enacted Title 18 (of the United States Code), Chapter 44, Section 922(r) which states 'it shall be unlawful for any person to assemble from imported parts any semi-automatic rifle or any shotgun which is identical to any rifle or shotgun prohibited from importation under Section 925(d)(3)...'
As indicated the section became effective on Nov. 29, 1990. Therefore, any assembly, performed after the effective date of the section, which creates a semi-automatic rifle that is prohibited from importation would be a violation of Section 922(r),
irrespective of the date that the firearm was imported.
This contradicts the common belief that rifles imported prior to November 29th, 1990 are immune from this legislation.
