Under $26$ U$.$S$.$C$.$ $ $5861($d$)$ it is a crime to possess certain kinds of "unregistered" firearms, such as sawed$-$off shotguns or machine guns. The term includes "destructive devices," such as grenades or "flash bang" devices. The crime is thus being in possession of a covered firearm without registering that possession with the appropriate federal agency. In United States v$.$ Berres, $777$ F$\mathrm{.}3$d $1083(10$th Cir. $2015)$ the defendant was convicted under this statute of carrying a flash bang device in his back pack. On appeal the defendant contended he could not be convicted for failure to register the de$-$vice, because the registration statute did not permit him to register the device. Is that a good argument?