I am about to get a form 1 approved for a SBR not yet efa10'd. This is my 1st SBR which wasn't already registered via efa10 prior to form1 being mailed. So the ATF knows it exists but the state of MA doesn't. In reading the MGL it clearly states you have 7 days to register a firearm or rifle in the online portal. Since MA doesn't define a sbr as either a rifle or a firearm doesn't that mean I'm under no legal obligation to register it? Prior thread here says to register it as a pistol but I'm confused by that logic. Can anyone educate me?