NFA Gun trust lawyer blog link
I found this... there is all kinds of helpful answers....
www.guntrustlawyer.com/shortbarreled-rifels-sbrs
SBR and TAX STAMP application and rules....
Okay so i found the magazine i read my earlier info. in...BLACK GUNS 2011. The column writer is Jeremy D.Clough, He goes through and documents the entire process... he states and i quote "As another word of warning, its worth noting that with a platform as modular as the AR15, "manufacturing" an SBR is as simple as pulling two pins and putting a short upper on your regular lower reciever. If you do that,even if you just want to see what one would look like on your rifle, you've just manufactured a class III weapon,and you're in violation of federal law. Similarily,if you if you possess an upper with a barrel shorter than 16",and you have a lower that it is physically possible for it to be assembled on, but which is NOT a registered SBR, you're in violation. Likewise,if you have a pistoland a shoulder stock that fits it-such as a stock for a glock-you're breaking the law. The same goes for vertical foregrips on handguns,such as putting a GriPod or Crimson Trace MVF on an AR pistol". And it goes on to tell how the same rules apply for individual LEO's and "Although the legal description for an SBR doesnt include the same exact language, the statue that defines a machinegun (which,like the SBR, is a class III weapon), includes any combination of parts that can be assembled to create one." " I expect the same reasoning to apply to combinations of parts that can be used to create an SBR,so if you don't have a lower that the upper can legally be mated with- such as an SBR or a registered pistol lower- you shouldn't have an upper with a barrel less than 16''. Again, I want to make it clear I wasnt saying anyone was wrong...i just heard two different things and wanted to let you guys know as well.