Shotguns: (D) a semiautomaticshotgun that has at least 2 of--
(i) a folding or telescoping stock;
(ii) a pistol grip that protrudes conspicuously beneath the action of the weapon;
(iii) a fixed magazine capacity in excess of 5 rounds; and
(iv) an ability to accept a detachable magazine.'.
The Linberta has only (ii), so I figure it's legal.