No. A firearm that was originally a rifle would be classified as a “weapon made from a rifle” if it has either a barrel less than 16 inches in length or an overall length of less than 26 inches. If an individual wishes to make an NFA firearm, they must first submit ATF Form 1 (Application to Make and Register a Firearm), pay a $200.00 making tax, and receive approval of the application from ATF before converting the firearm.
[18 U.S.C. § 921(a)(3); 26 U.S.C. § 5845(a)(3)-(4)]