Sect. 922r is the last remnant of the Assault Weapon Ban. Yes, it still is law. If you have more than 2 of the dreaded/evil assault weapon features (Detachable high cap mags, Flash hider, Bayonet lug, Protruding pistol grip and collapsable or folding butt stock) you can have no more than 10 imported parts. There is a list of parts that are counted, I just cannot find it right now. The exact number of US parts varies depending on the firearm.
922r is a Federal law. State and Local LE do not enforce it (although you might run into an overzealous yokel). The real risk is if you are forced to use the rifle to defend yourself. Once it is in evidence the ATF will likely be consulted about the rifle's legality. THEN you have problems.
In life, strive to take the high road....It offers a better field of fire.
"Robo is right" Fuzzball