Gkgeiger, you could have added a $50 Shockwave brace or a $100 Sig brace to your MPX without a tax stamp. The NFA stamp is definitely the "Right" way to go, just takes more time, money and effort. And don't forget, having the collapsible stock or foregrip in the vicinity of the Sig pistol may be a Constructive Possession violation depending on where you live, meaning you have all the parts for the NFA weapon before the stamp is received. So keep the stock and foregrip at a buddy's or relative's house until the stamp is received. Phil
Florida Statue 790.221
(1) It is unlawful for any person to own or to have in his or her care, custody, possession, or control any short-barreled rifle, short-barreled shotgun, or machine gun which is, or MAY READILY BE MADE operable; but this section shall not apply to antique firearms.
(2) A person who violates this section commits a felony of the second degree, punishable as provided in s. 775.082, s. 775.083, or s. 775.084.
(3) Firearms in violation hereof which are lawfully owned and possessed under provisions of federal law are excepted.