You can, but be aware that an exploding cannonball (widely available in 1776) is considered a destructive device, so each shell must have an NFA stamp. Solid shot is not considered a destructive device.
Does the shell have to be serialized? Or does one merely need a stamp that handwaves towards a particular, but generic looking shell?
Does the shell have to be serialized? Or does one merely need a stamp that handwaves towards a particular, but generic looking shell?