If you were to do a Form 1 to short barrel a Benelli M1014 and get approved, could you then install a larger mag on it (with a pistol grip stock)?    Or would you still have to comply with the 1989 law?

With an approved Form 1 i am pretty sure you can do whatever you want in reguards to a mag extention and pistol grip.  If your wanting something small like that you may look into the AOW route.  You cannot put a stock on it, but if your intention is to use a pistol grip only then it will save you 195.00 in a tax stamp.  Still takes awhile to get it approved.  Serbu makes good AOW shotguns from what i have been told.  This is all just from my personal knowledge, don't take it as truth best bet is call a class III dealer or even the ATF.

-HSP
  Merry Christmas  

Quoted: If you were to do a Form 1 to short barrel a Benelli M1014 and get approved, could you then install a larger mag on it (with a pistol grip stock)?    Or would you still have to comply with the 1989 law?

NFA firearms are exempt from 922(r), so you'd be able to add a working telestock and magazine extension legally.

Quoted: If your wanting something small like that you may look into the AOW route.  You cannot put a stock on it, but if your intention is to use a pistol grip only then it will save you 195.00 in a tax stamp.

Both SBS and AOW cost $200 to manufacture.

But as mentioned above, you could not convert a shotgun into an AOW unless it has never had a buttstock on it. Gotm4 is just concerned about having both a pistol grip and mag extension on an imported shotgun. It sounds to me like he's planning on using a buttstock that has a pistol grip.