I was wondering where one can obtain the forms necessary to purchase an NFA firearm or suppressor and how one would go about asking one of the eligible officials to sign off on the purchase (as a signature is necessary). Has anyone any information on coastal guns and their suppressors? I was looking into the Ultima. "1) A standard thread mount interface or 2) R.A.D. (Recoil Attenuation Device)" And I was wondering if someone could explain what R.A.D Recoil attenuation Device means and does.