It’s not administrative, but legislative. ATF is empowered to interpret these laws. The law is quite clear that a howitzer is regulated. https://en.wikipedia.

It’s not administrative, but legislative. ATF is empowered to interpret these laws. The law is quite clear that a howitzer is regulated. https://en.wikipedia.org/wiki/Destructive_device https://en.wikipedia.org/wiki/Destructive_device