First, the requisite disclaimers that are necessary in today's world: This should not be construed as professional legal advice. This is the result of years of accumulating knowledge on the subject. Legal advice will confirm these laws but here they are all in a straightforward form so you know what to confirm should you require professional legal counsel. A question often asked is what is legal to do to an SKS now that the '94 phony Assault Weapon Ban has expired. The good news is that yes, some things are legal that were not during the ban. The bad news is that not every law restricting modification to an SKS has expired. Here are the basic four major federal gun laws of the 20th century: 1934: National Firearms Act (NFA) - Forces rifles, shotguns, and pistols into narrow categories based on length of barrel and overall, and the presense of a stock. While extensive, its application to the SKS is brief. Basically as a rifle it must have a barrel length of at least 16" (including any permament attachment to the barrel) measured from the bolt face with the bolt closed. Stick a rod down the barrel and measure how deep it goes, and then add a bit for good measure, that's how the BATF measures it. There is no way to exempt it from these requirements by classifying it as a pistol since it was originally made as a rifle. The NFA also restricts silencers. Shortening the barrel beneath 16" or owning any silencer requires a $200 tax be paid to the ATF and registration submitted BEFORE the fact. Do not think of ever making an SKS fully automatic. It is also restricted under the NFA but has been illegal period since 1986. It is also extremely unsafe as most full auto mods to the SKS involve disabling mechanisms that prevent it from firing out of battery (a very dangerous thing). Even if safe, the SKS was not built for sustained rapid fire. The Palestinians tried modding them for this, in battle their SKSs promptly caught fire. In summary: Keep your SKS barrel at 16", overall length 26", buy your silencers legally and be prepared for taxes and paperwork, and tell anyone who suggests making an SKS full auto to stay far away from you. 1968: Gun Control Act (GCA) - Places requirements on firearms ownership and creates authority for importation restriction. No specific restrictiosn based on features but it creates the powers later used to make subsequent abusive restrictions based on features. 1989: Import Ban - Creates a blank check for the executive to ban any imported guns not considered "sporting". Reasons for banning dramatically increased during the Clinton Administration. Every couple years they added something on, so you'll find plenty of grandfathered guns that predate one redefinition or another, from banning pistol grips, bayonets (not lugs), folding stocks, then later to military magazines. Examples of these include the SKS-M (AK magazine model), the Norinco MAK-90, several Romanian AK models, certain variants of the FAL and G3, and SKSs placed into aftermarket thumbhole stocks with their bayonets removed. If you get one you cannot change its features and still comply with this law. The good news is that this law can be avoided by making your gun count as US made. At one point, a person could assemble a banned rifle from imported parts without trouble. At another point, any imported part made a rifle count as imported and subject to restrictions. In order to prevent easy assembly from parts but not criminalize a German screw in your AR-15, they came up with a list of 20 parts that count. Of these 20 parts, one may have ten or less for it to count as US made. If the gun never had it to begin with, you're basically one part ahead. This list consists of: 1. Barrels (US available, not worth it) 2. Receivers 3. Muzzle attachments (exists only on Yugo M59/66, US made available) 4. Barrel extensions (doesn't exist on SKS) 5. Bolts 6. Bolt carriers 7. Gas pistons (US available at Tapco 8. Operating rods (This is the secondary piston, US available at Tapco) 9. Trunions (doesn't exist on SKS) 10. Triggers 11. Trigger housings 12. Sears 13. Disconnectors 14. Hammers 15. Buttstocks (Variety of Polymer US stocks available) 16. Pistol grips (not originally on SKS, but integrated to US made folders) 17. Handguards (US available with stocks) 18. Magazine bodies (US available) 19. Magazine floorplates (US available) 20. Magazine followers (US available) Out of 16 parts (or 17 for M59/66 Yugo), there are just enough US made replacement parts to bring the count down to 10 or less. 1994: The Assault Weapon Ban (AWB) - Regardless of the claims of the media, this has nothing to do with full automatics. This banned semi-automatics not by features, but by combinations of features. It affected shotguns, pistols, and rifles differently. For a rifle, it said that: Any semi-automatic rifle with a detachable magazine could legally have only one of the following features: 1. Pistol grip (thumbhole stocks were found to be p-grips in 1996, but accepted still as "sporting" pistol grips for import. Thus MAK-90s made it into the country but still had their one banned feature used up.) 2. Folding stock 3. Bayonet lug 4. Flash hider or threads for one 5. Grenade launcher It also banned new manufacture of magazines over 10 rounds. Rifles and magazines that existed before that law that would otherwise be in violation were grandfathered, but resultantly went up in value due to their numbers being limited by the ban. It effectively banned folding stocks because having one is practically impossible without a pistol grip as well. The AWB expired in September 2004, but some states adopted it as their own before then. NY is an example. So there you have it. In order to add any previously restricted features, you must make sure it is first in US parts compliance. The good news with the SKS is that most of the parts that would add restricted features are made only in the US. For example pistol grip/thumbhole/folding stocks and detachable magazines. Be advised that many states have laws on top of the federal ones, so be aware of possible complications they cause before thinking you're good to go. Now in addition to those laws, there is a general consensus among mature gun owners that making such changes to an SKS is probably not worth it. The money spent on these accessories could be spent on an AK which would do the job much much better. The original fixed mag is the most reliable feeding device and the ergonomics of the folding stocks are questionable at best. Finally, removing an SKS from military configuration is considered by many to be butchering a classic rifle. But it's not illegal as long as you watch your imported parts count. Keep your mods legal, your shooting responsible, and your home safe! And of course if any mistakes are here, please post and I will edit.