N.H. Rev. Stat. § 159-E:1
Pursuant to the general court's authority under Part II, Article 5 of the New Hampshire Constitution, the state of New Hampshire, a political subdivision of this state, or any person acting under the color of state, county, or municipal law shall be prohibited from using any personnel or financial resources to enforce, administer, or cooperate with any law, act, rule, order, or regulation of the United States Government or Executive Order of the President of the United States that is inconsistent with any law of this state regarding the regulation of firearms, ammunition, magazines or the ammunition feeding devices, firearm components, firearms supplies, or knives. Silence in the New Hampshire Revised Statutes Annotated pertaining to a matter regulated by federal law shall be construed as an inconsistency for the purposes of this chapter.
RSA 159-E:1