High capacity magazine question?

I do not have a direct source to verify this, but yes.

I believe Colt (?) was stamping their AR lowers with this statment during the AWB. After it was lifted, there was/is nothing preventing civilians owning them (and it's not like Colt went back and un-stamped them... lol).

Yes... I have a bunch of them that I bought in Sept 2004 - CHEAP!!!

I've been reading a couple of books by Patrick Sweeney. He covers this issue and says they're fine to use.