it does seem like it protrudes conspicuously beneath the action of the weapon just because the stock is attached to the grip part doesnt make that section of the stock not a pistol grip in fact ive seem much advertisement about montecarlo stocks having a pistol grip vs the straight stock
it would be cool if it was deemed legal and have one made for the thompson that way i could use my 40 round drum and 20 round sticks
i want to know how that handguard is attached
http://monstermangrip.com/Legal_Info.html