Hello, I'm new to the forum - but not to gun laws.
In terms of the Shockwave and the new AR "other firearm" models, the secret sauce is the specific configuration. The OAL, the specific; non-typical barrel length, the lack of a "stock" and the mandatory front vertical grip assembled on a properly designated lower create the legal firearm.
Those who want to cost cut, or feel they can build a better gun - enjoy.
The Troy A4 NJ "other firearm" will be available after this weekend. Call TechOps International at 908-454-6030 with questions or to pre-order.