Brazos_Jack,
You are correct that the Mossberg Shockwave is not classified as a shotgun (otherwise its length would render it an NFA item). The ATF was clear that the Mossberg Shockwave IS a firearm and IS NOT a short-barreled shotgun. Some people speculate this item may be a pistol. But the federal definition “designed to be fired with one hand,” does not perfectly fit the Mossberg Shockwave, which is capable of being fired with one hand but probably not designed to do so. Similarly, in Texas, this gun most closely falls under the category of a handgun, but it is still unclear. Because there is no judicial or administrative guidance on the classification of the Shockwave, we recommend concealing it in a case or sheath or transporting it in your trunk.