Could someone help me on the legality of a scenario: if I bought just one cqb length mrp upper, could I use this with a 16 inch barrel for my  rifle lower and a 10.5 inch barrel for my pistol lower, or would this make the rifle an sbr because they are common parts, I am just trying to see how much practicality I can get for a 1300 dollar upper (everyone needs help justifying a purchase like that, and I'm no different).

wow that is a good question

tag for answers

as long as the 10.5 never makes it on a non sbr lower i dont see the problem with it.


the lower is the controlled part not the rest.

As far as I know, Eklikwhoa is right: an upper is considered just "parts", neither pistol nor rifle.