No Rico they are not registered, not unless you live in Ca and even then you only have to register AR types and handguns. Let me ask you a question. Do you currently have to have a license to own a firearm of any kind? When we give the right up to own them freely, we won't be free much longer.
A form 4473 does not equal registerd gun. In fact, according to the law, the form cannot be used later to identify owners unless needed in the solving of a crime.......which refusal to register would be a crime wouldn't it???