N.H. Rev. Stat. Ann. § 111:15

No organization, society, club, post, order, league or other combination of persons, or civil group, or any members thereof, are authorized to assume any semblance of military organization or character by bearing or possessing rifles, pistols, sabres, clubs, or military weapons of any kind, or wearing a military uniform of any kind. Any person violating any of the provisions of this section or taking part in such military organization shall be guilty of a misdemeanor if a natural person, or guilty of a felony if any other person; and any rifles, pistols, sabres, clubs or other military weapons used in violation hereof shall be forfeited. This section shall not apply to regularly constituted military units under state or federal laws; and nothing in this section shall be construed as forbidding the possession and use of rifles for color guards or firing squad purposes, or the wearing of uniforms of a military character, by an organization composed wholly of veteran soldiers who participated in any war of the United States, or by any other recognized fraternal group of long-standing in the community which uses rifles or sabres merely as a part of its ritualistic exercises and which is not specifically disapproved by the President of the United States, the Department of Defense, or the governor.