yes a shotgun under 16 inches is illegal however the shockwave is not classified as a Shotgun by the ATF it is just a firearm making it legal if you are 21 or older "no it is not classified as a shotgun or pistol it is just classified as a firearm "the Shockwave is classified by the ATF as a “firearm” and available to shooters without having to buy a tax stamp or fill out paperwork" range365.com/mossberg-shockwave-gun-test#page-5"

Harold, The Shockwave hit the loophole for a "firearm". It was manufactured in the over 26" total length as a firearm. The Shockwave is not a shotgun.

Harold, They're openly sold everywhere in Florida and the ranges allow you to shoot them. I wouldn't give it a second thought. Remember it i classified as a "Firearm" and not a "Shotgun".