Um, what are you talking about? Suppressors are not firearms and are the only NFA item you can legally transport across state lines without paperwork. Also S&S on what? The NFA/ ATF searches and inspections apply to dealers. 15 years of owning 2 cans, a SBR and SBS and never have I been searched because of them or for any other reason.It's not just "paperwork", but signing off on letting drop a lot of rights protecting against search and seizure, as well as free transit and disposal of personally owned property. This why I have never messed with one.