Is this still valid, or has the ATF made a ruling on this that I'm not aware of recently? Something mentioned by an administrator on one of the forums I frequent contradicts this, and I wanted to be sure since I couldn't find anything on the ATF site or in the U.S. Code that contradicts the quoted information below.

Quote Originally Posted by ATF Website
While a receiver alone may be classified as a “firearm” under the Gun Control Act (GCA), SBRs and SBSs are classified in totality under the National Firearms Act (NFA). A firearm that meets the definition of a SBR consists of a rifle that has a barrel less than 16 inches in length. A SBS consists of a shotgun that has a barrel less than 18 inches in length..
http://www.atf.gov/firearms/faq/nati...-shotguns.html

The below quote is what makes me ask this, and is in reference to a 1911 carbine kit.

Quote Originally Posted by NAME REDACTED
Are you sure the barrel is 16 1/4? If it is you are in possesion of a SBR which needs to be regustered with the ATF.