That's the gun type he co-sponsored to ban, bill S. 1431, last year ("The Assault Weapons Ban and Law Enforcement Protection Act of 2003) which would have banned a "semiautomatic shotgun that has a pistol grip."

The "pistol grip," as loosely defined in the bill. [Section SEC. 2; (H) (ii) and (b)(42): "The term 'pistol grip' means a grip, a thumbhole stock, or any other characteristic that can function as a grip."]