The way the electoral roll is managed varies from place to place.
Avoiding automatic voter registration tends to favour the more traditionally conservative demographic; it's racist and classist, but the people who turn up to vote on local electoral issues are too, by and large. It requires engagement to change.
It comes to the same conclusion regarding the illegality of the weapons, even if it's pretty lenient in its interpretation of how thousands of devices can be "reasonably expected" to all end up in the hands of combatants.