Got an interesting question here, about the confusing "assault weapon ban" laws, that not even most of our police officers seem to understand.
Folding/collapsible stocks are one of the prohibited items (when in combination with things like a pistol grip, flash suppressor, removable magazine, etc) unless installed on a pre-ban firearm.
How about a folding stock for the Ruger 10-22? I was recently told by a gun shop owner that it can be installed on one of any year, because the assault weapon laws don't apply to a rifle that uses rimfire cartridges.
Seems bizarre to me... but would be no more bizarre than some of the other silliness in those incomprehensible laws. I'm sure someone here has a better understanding of the laws than I do, and could tell me if this is complete and utter BS, or if it is the truth.
Last thing I want to do is find myself in violation of a federal firearm law, in the hands of an overzealous police officer.