As a further note, if the ATF decides that the Shockwave guns need tax stamps I will wager that they will not grandfather any of them and every single one will require a $200 tax stamp unless the ATF says they are "AOWs", in which case it is just extra paperwork and $5.00 tax stamp. Every owner of every single one of them will have to pay the tax or become a felon. There will be a grace period for it, presumably.