Doyle, It the state of WA, Article 1 Section 24 of the STATE constitution...
SECTION 24 RIGHT TO BEAR ARMS. The right of the individual citizen to bear arms in defense of himself, or the state, shall not be impaired, but nothing in this section shall be construed as authorizing individuals or corporations to organize, maintain or employ an armed body of men.
My bold...It would be very difficult to say that carry for self defence, under the laws of the state (WA) at least if the NP was in WA, that self defence was not a "lawful purpose" Eh, you think?
The majority of states have similar wording in their constitutions